Severe nodulo-cystic acne (Grade IV)
A severe inflammatory skin condition characterised by nodules and deep, painful cystic lesions, predominantly affecting the face and trunk. Comedones and superficial inflammatory lesions may also be present.
Visual differential diagnosis of skin and mucosal lesions
DxVisual is a differential diagnosis support tool based on the visual and clinical characteristics of lesions. It allows users to select location, lesion type, symptoms, duration, evolution, colour, surface, distribution pattern, age and specific findings, presenting compatible diagnoses together with clinical images and additional information.
The tool was developed to facilitate a structured approach to skin, nail and mucosal lesions, as well as other visually recognisable clinical abnormalities. Results should be interpreted in the context of the clinical history and physical examination and do not replace medical assessment or complementary investigations when indicated.
FAQ
1. What is DxVisual?
DxVisual is a visual differential diagnosis support tool that allows clinical and morphological characteristics of a lesion to be related to different possible conditions. The search can be refined by location, lesion type, symptoms, duration, evolution, colour, surface or consistency, distribution pattern, age and specific findings.
2. How does visual differential diagnosis work?
Select one or more characteristics observed in the lesion. The matrix automatically adapts to the selected criteria and displays only the options related to diagnoses that remain compatible. Results are updated in real time and presented with a clinical image and additional information.
3. Can I combine several filters?
Yes. You can combine different clinical characteristics to make the differential diagnosis progressively more specific. For example, you can select a location, a lesion type, a specific colour and a distribution pattern. As you add criteria, the results and the remaining matrix options are automatically updated.
4. What are specific findings?
Specific findings are characteristics that are particularly useful for distinguishing certain conditions, such as telangiectasias, nail pitting, grouped vesicles, honey-coloured crusts, Nikolsky sign, dendritic ulcer or other characteristic clinical signs. They can be used to refine the differential diagnosis when present.
5. What information is shown in the results?
Each result displays a clinical image and the name of the condition. When you open a result, you can view the clinical description, differential diagnosis, usual locations, warning signs and additional images when available. Whenever further content is available on the platform, a link to the corresponding clinical page or algorithm may also be provided.
6. Does DxVisual confirm the diagnosis?
No. DxVisual is a clinical reasoning support tool and does not replace medical assessment. Results should be interpreted together with the clinical history, physical examination, lesion evolution and complementary investigations when indicated.
7. Why might a condition not appear in the results?
Some conditions may present atypically or with characteristics different from their most common presentation. A very restrictive combination of filters may also exclude relevant diagnoses. In these cases, review the selected criteria, remove less specific characteristics or restart the search.
8. What types of conditions are included?
DxVisual includes different dermatological conditions and other disorders with visually recognisable manifestations, including abnormalities of the skin, nails, mucosae, genital region, oral cavity, eyes and ears. The diagnostic database is structured according to clinical and morphological characteristics relevant to differential diagnosis.
9. Where do the images come from?
The clinical images used in DxVisual are accompanied, whenever available, by identification of their respective original source. Images should be interpreted as illustrative material, since the presentation of the same condition may vary between patients.
10. Can I use the images in presentations or publications?
Reuse of the images depends on the rights associated with the original source. Before using any image outside the platform, you should consult the respective source and confirm the licence, attribution and reuse conditions.
Images/diagnoses
Diagnoses included in DxVisual
DxVisual includes 147 diagnoses and clinical presentations with visually recognisable manifestations of the skin, nails, mucosae, oral cavity, eyes and ear. The descriptions below summarise the most relevant clinical and morphological characteristics to support visual differential diagnosis.
Kawasaki disease
An acute systemic inflammatory syndrome that mainly affects children, characterised by persistent fever associated with mucocutaneous involvement. It frequently presents with a diffuse erythematous rash, which is sometimes confluent and symmetrical, oral changes such as erythematous or fissured lips and a ‘raspberry’ tongue, as well as bilateral conjunctival hyperaemia.
Inguinal granuloma (Donovanosis)
A chronic, sexually transmitted bacterial infection, characterised by lesions that are initially papulonodular and progress to painless, progressive and destructive ulcers, usually located in the genital or perianal region.
Scabies – nodular lesions
Erythematous-violaceous nodules, which are very itchy, firm and clustered, typical of a hypersensitivity reaction to Sarcoptes scabiei. They appear mainly in skin folds and may persist for weeks after treatment, often accompanied by excoriations and residual hyperpigmentation.
Scabies
A skin infestation caused by the mite Sarcoptes scabiei, characterised by intense itching, typically worse at night, associated with erythematous papules, excoriations and, occasionally, small vesicles.
Crusted scabies (Norwegian scabies)
A severe form of scabies characterised by thick, crusted and adherent hyperkeratotic lesions, often yellowish-white in colour, mainly affecting the hands, fingers, interdigital spaces, periungual regions and, occasionally, extensive areas of the skin.
Cholinergic urticaria
Recurrent episodes of small, erythematous, urticarial papules that are intensely itchy and sometimes accompanied by a burning sensation, typically triggered by an increase in body temperature, such as during physical exercise, exposure to heat, a hot bath or emotional stress.
Cold-induced urticaria
Recurrent episodes of erythematous, oedematous and pruritic urticarial papules or plaques, triggered by exposure to the cold, including cold air, cold water or contact with cold objects.
Dermographic urticaria (dermographism)
Recurrent episodes of urticarial papules or linear plaques triggered by mechanical stimulation of the skin, such as friction, pressure or scratching. The lesions usually appear within a few minutes of the stimulus; they are erythematous, oedematous and pruritic, and follow the path of the mechanical contact.
Angioedema
Acute episodes of deep oedema of the dermis and subcutaneous tissue, often affecting the lips, eyelids and mucous membranes. This may be accompanied by a sensation of tightness or pain, usually without itching, and resolves spontaneously within hours to days.
Urticaria
Erythematous, oedematous and well-defined urticarial papules and plaques, which appear suddenly and are usually very itchy. The lesions are migratory and transient, generally lasting from a few minutes to a few hours before disappearing without leaving any residual lesions, and may appear in other locations.
Rosacea
A chronic inflammatory skin condition of the face, characterised by persistent or recurrent erythema in the central facial area, episodes of flushing and, in some forms, the presence of papules and pustules.
Hidradenitis suppurativa
A chronic inflammatory disease of the pilosebaceous units, characterised by deep, painful nodules, recurrent abscesses and the formation of fistula tracts with purulent drainage.
Miliaria
A dermatosis caused by the obstruction of sweat ducts, characterised by small superficial papules or vesicles, which are often itchy or accompanied by a burning sensation, and which mainly occur in hot, humid conditions and during heavy sweating.
Chancroid (male)
A painful genital ulcer with an acute onset, which may be single or multiple, usually with irregular edges and an exudative or dirty base. It is caused by Haemophilus ducreyi and is transmitted through sexual contact.
Chancroid (female)
A painful genital ulcer with an acute onset, which may be single or multiple, usually with irregular edges and an exudative or dirty base. It may be located on the labia, in the vestibule, or in the perineal or perianal region.
Genital herpes (in women)
A viral infection caused by the herpes simplex virus, characterised by clusters of vesicles on an erythematous base in the genital region, which can rapidly progress to painful erosions and ulcers.
Lymphogranuloma venereum
A sexually transmitted infection caused by Chlamydia trachomatis serovars L1–L3. The initial stage is usually characterised by a small genital papule, vesicle or ulcer, which is generally painless and self-limiting, and may go unnoticed.
Genital herpes (in men)
A viral infection caused by the herpes simplex virus, characterised by clusters of vesicles on an erythematous base in the genital region, which can rapidly progress to painful erosions and ulcers.
Primary syphilis (male)
A genital ulcer that is usually solitary, painless, well-defined and has a firm or indurated base, corresponding to the chancre of primary syphilis. It usually appears after an incubation period of a few weeks and may be located on the glans, foreskin or other areas of sexual contact.
Secondary syphilis (hands)
Multiple maculopapular lesions, pink, erythematous or brownish in colour, distributed across the palms of the hands and frequently also on the soles of the feet. They are usually symmetrical, non-pruritic and asymptomatic, and may have a smooth surface or show slight scaling.
Secondary syphilis (generalised rash)
A diffuse maculopapular rash, usually not itchy, mainly affecting the trunk and limbs, and possibly involving the palms of the hands and soles of the feet.
Tertiary syphilis (syphilitic gumma)
Chronic granulomatous lesions corresponding to syphilitic gummata, usually presenting as firm or indurated nodules that may progress slowly to ulceration, necrosis and tissue destruction.
Lichen sclerosus
A chronic inflammatory dermatosis characterised by whitish, atrophic and sometimes sclerotic plaques, predominantly affecting the anogenital region. It is frequently associated with intense itching, a burning sensation, pain, fissures and skin fragility.
Bowenoid papulosis
Multiple papular, erythematous, brownish or hyperpigmented lesions, generally well-defined and with a verrucous or papillomatous surface, located in the anogenital region and associated with HPV infection, usually of the high-risk type.
Queyrat’s erythroplasia
A well-defined, persistent erythematous patch with a smooth, glossy or slightly eroded surface, usually located on the glans or the inner foreskin. This corresponds to squamous cell carcinoma in situ of the male genital mucosa.
Candida balanitis
Inflammation of the glans, often involving the foreskin, caused by Candida spp. It is characterised by local erythema, a burning sensation or itching, and may be associated with a whitish exudate, maceration and small satellite lesions.
Zoon’s balanitis
A well-defined erythematous or orange-red patch with a smooth, shiny surface, usually located on the glans or the inner foreskin, characteristic of Zoon’s plasmacytic balanitis.
Circinate balanitis
Annular, polycyclic or serpiginous erythematous lesions, generally superficial and causing few symptoms, located on the glans and in the balanopreputial sulcus. They may present with erosive areas and well-defined borders.
Grade 1 acne (closed comedones)
A predominantly comedonal and non-inflammatory form of acne, characterised by the presence of multiple closed comedones, visible as small whitish or skin-coloured papules, without significant erythema.
Grade 1 acne (open comedones)
A predominantly comedonal and non-inflammatory form of acne, characterised by open comedones, visible as blackheads due to the oxidation of the follicular contents when exposed to air.
Grade 2 acne
A mild to moderate inflammatory form of acne, characterised by erythematous papules and pustules associated with open or closed comedones. The lesions are predominantly found on the face, but may also affect the chest and back.
Grade 3 acne
A moderate to severe inflammatory form of acne, characterised by papules, pustules and deeper inflammatory nodules. The lesions are generally more numerous, painful and infiltrated than in grade 2 acne; they are predominantly found on the face and may also affect the chest, back and shoulders.
Mediterranean spotted fever (palmar exanthema)
An acute maculopapular rash associated with fever, malaise and other systemic symptoms, usually affecting the trunk and limbs, and possibly extending to the palms of the hands and soles of the feet.
Mediterranean spotted fever (tache noire lesion)
A characteristic inoculation lesion of Mediterranean spotted fever, known as ‘tache noire’, consisting of a necrotic scab with a dark or black central crust, surrounded by an erythematous halo.
Mediterranean spotted fever (generalised rash)
An acute, diffuse and usually symmetrical maculopapular rash, mainly affecting the trunk and limbs and which may extend to the palms of the hands and soles of the feet.
Mononucleosis (exudative tonsillitis)
Acute exudative tonsillitis characterised by a whitish or yellowish exudate on the tonsils, associated with fever, odynophagia and cervical lymphadenopathy. Marked malaise is common, and petechiae may occur on the palate.
Mononucleosis (morbilliform rash)
A diffuse maculopapular rash, of a morbilliform pattern, frequently associated with fever and malaise, mainly affecting the trunk and limbs. It may be slightly itchy and arise spontaneously in the context of infectious mononucleosis; it is particularly common following administration of aminopenicillins, such as amoxicillin or ampicillin.
Scarlet fever (rash on the face with pallor around the mouth)
A diffuse erythematous rash associated with fever and odynophagia, with facial involvement characterised by flushing of the cheeks and perioral pallor, corresponding to Filatov’s sign.
Scarlet fever (strawberry tongue)
Mucosal changes characteristic of scarlet fever, with an intensely erythematous tongue and prominent papillae, giving it the typical ‘strawberry tongue’ appearance. It usually occurs in association with fever, odynophagia and pharyngotonsillitis, and may coexist with a diffuse scarlet fever-like rash, a ‘sandpaper’ skin texture and perioral pallor.
Scarlet fever (rash)
A diffuse, erythematous, micropapular rash, fine and rough to the touch, with a characteristic ‘sandpaper’ texture, usually associated with fever and odynophagia. It usually begins on the trunk and in skin folds, subsequently spreading to the limbs, with a marked presence in the folds.
Measles (maculopapular rash)
An erythematous maculopapular rash that usually begins on the face and behind the ears, spreading cephalocaudally to the trunk and limbs. It is associated with fever, cough, a runny nose and conjunctivitis, and may become confluent as the condition progresses.
Measles (Koplik spots)
Small whitish or bluish-white macules, with an erythematous halo, typically located on the buccal mucosa, particularly opposite the molars. They appear during the prodromal phase of measles, usually before the onset of the skin rash, alongside fever, cough, runny nose and conjunctivitis.
Roseola infantum (exanthem subitum)
A pink maculopapular rash that typically appears after a high fever has subsided, predominantly on the trunk and which may extend to the neck and proximal limbs.
Infantile Papular Acrodermatitis (Gianotti-Crosti Syndrome)
A monomorphic, symmetrical papular rash, predominantly affecting the face, buttocks and extensor surfaces of the limbs, often with relative sparing of the trunk. The lesions may be mildly itchy and usually appear in young children, often following a viral infection.
Chickenpox
An intensely itchy vesicular rash, with lesions at different stages of development — macules, papules, vesicles and scabs — predominantly on the trunk, scalp and face, spreading to the limbs.
Hand, foot and mouth disease
A viral disease characterised by papules and vesicles on the hands and feet, often including the palms and soles, associated with vesicular or ulcerated lesions in the oral cavity.
Unilateral Lateral Thoracic Rash
Unilateral maculopapular rash, usually located on the lateral aspect of the chest, frequently starting near the armpit and possibly spreading centrifugally to the ipsilateral arm and trunk.
Pityriasis rosea
A self-limiting inflammatory dermatosis often characterised by an initial single lesion, the ‘heraldic plaque’, followed a few days later by multiple oval, erythematous-pink, finely scaling plaques or macules.
Infectious Erythema (Parvovirus B19)
A viral rash characterised by intense facial erythema, with the typical ‘slapped cheeks’ appearance, often sparing the area around the mouth, followed by a reticulated maculopapular rash on the limbs and trunk.
Rubella
A pink maculopapular rash that usually begins on the face and spreads rapidly to the trunk and limbs. It may be associated with a low-grade fever, malaise and lymphadenopathy, particularly in the retroauricular, occipital and posterior cervical regions.
Acute otitis media
Acute middle ear infection, usually associated with earache, fever and temporary hearing loss. On otoscopy, the most suggestive finding is bulging of the tympanic membrane, often accompanied by opacification, erythema and reduced mobility; a fluid-air level or otorrhoea may be observed where there is a tympanic perforation.
Serous otitis media
Presence of fluid in the middle ear without signs of acute inflammation. It manifests itself mainly as conductive hearing loss, a sensation of a blocked ear, or changes in attention and speech in children. On otoscopy, the tympanic membrane may appear retracted, opaque or amber-coloured, with a water-air level or bubbles and reduced mobility, usually without significant bulging.
Eczema of the external auditory canal
Dermatitis of the external auditory canal characterised by itching, redness and scaling of the canal, which may be associated with fissures, a sensation of a blocked ear and mild discomfort.
Otitis externa
Acute infection of the external auditory canal characterised by earache, which is often severe and aggravated by movement of the auricle or pressure on the tragus, associated with oedema and erythema of the canal.
Acute mastoiditis
A suppurative complication of acute otitis media characterised by inflammation of the mastoid cells, with pain, oedema and retroauricular erythema, often accompanied by fever.
Retroauricular eczema (with secondary infection)
Eczematous dermatitis of the retroauricular region with signs of bacterial superinfection, characterised by erythema, fissures, erosions, scabs and exudate, frequently associated with intense pruritus and local pain.
Otomycosis
A fungal infection of the external auditory canal, usually characterised by severe itching, a feeling of a blocked ear and, occasionally, mild earache or hearing loss. On otoscopy, fungal debris is observed in the canal; this may be dark or black in Aspergillus infections, or whitish/yellowish in Candida infections.
Gouty tophus
Chronic deposits of monosodium urate crystals forming firm, generally painless subcutaneous nodules, located mainly in peripheral joints and periarticular tissues. Tophi are most commonly found on the fingers, elbows, feet and outer ear, and may cause pain, functional impairment, joint deformity or ulceration when large.
Gout
Acute inflammatory arthritis with sudden onset, characterised by severe pain, swelling, warmth and redness of the joint. The first metatarsophalangeal joint is the classic site (gout), but the ankle, knee, midfoot and other peripheral joints may also be affected.
Bacterial tonsillitis
Acute pharyngotonsillitis of probable bacterial aetiology, characterised by odynophagia, fever and oropharyngeal erythema, often with exudate or plaques on the tonsils. It may be associated with tender anterior cervical lymphadenopathy and the absence of a cough or other marked respiratory symptoms.
Peritonsillar abscess
A suppurative infection of the peritonsillar space, usually unilateral, characterised by severe odynophagia, referred pain to the ear, fever and trismus. On examination, asymmetric bulging of the soft palate/peritonsillar region is observed, often with contralateral deviation of the uvula and a muffled, ‘hot potato’-like voice.
Herpangina
An acute viral infection characterised by small vesicles that rapidly develop into painful ulcers in the oropharynx, particularly on the soft palate, the uvula and the tonsillar pillars.
Tonsillar caseum (tonsillolith)
An accumulation of food debris, shed cells and keratin in the tonsillar crypts, forming small whitish or yellowish deposits with a crumbly consistency, known as caseous deposits or tonsilloliths.
Keratin cyst on the tonsils
A well-defined cystic lesion, usually whitish or yellowish in colour, located on the palatine tonsil and filled with keratinous material. It is usually asymptomatic, but may cause a foreign-body sensation or oropharyngeal discomfort.
Viral tonsillitis
Acute pharyngotonsillitis of viral aetiology, characterised by diffuse erythema of the tonsils and oropharynx, often associated with a cough, rhinorrhoea, hoarseness, conjunctivitis or other respiratory symptoms.
Diphtheria
A potentially serious bacterial infection characterised by the formation of a thick, adherent, greyish-white pseudomembrane in the oropharynx, often involving the tonsils, pillars and pharyngeal wall.
Erythema nodosum
An inflammatory panniculitis characterised by erythematous, painful and poorly defined subcutaneous nodules, located predominantly on the anterior surface of the legs, particularly in the pretibial region.
Acute cutaneous lupus (malar rash)
Symmetrical malar erythema with a ‘butterfly wing’ distribution, involving the malar regions and the bridge of the nose, typically sparing the nasolabial folds.
Acute cutaneous lupus (photodistributed rash)
Symmetrical macular or plaque-like erythema, predominantly located in sun-exposed areas, including the face, neck, décolletage and extensor surfaces of the upper limbs. It is often triggered or exacerbated by sun exposure and does not leave scars.
Subacute cutaneous lupus (annular lesions)
Annular or polycyclic erythematous lesions, often with peripheral scaling and central depigmentation, distributed predominantly over sun-exposed areas of the upper trunk and limbs.
Subacute cutaneous lupus (papulosquamous lesions)
Erythematous papulo-scaly lesions, often confluent and psoriasiform in appearance, distributed predominantly over sun-exposed areas of the upper trunk and upper limbs. They may cause mild itching or a burning sensation and have a subacute or recurrent course.
Chronic cutaneous lupus (discoid lesions)
Well-defined erythematous plaques, often with adherent scaling and follicular hyperkeratosis, which progressively develop into central atrophy, scarring and pigmentary changes. They predominantly affect the face, scalp and auricles, and may cause scarring alopecia when they affect hair-bearing areas.
Chronic cutaneous lupus (scarring alopecia)
Areas of permanent scarring alopecia on the scalp, associated with erythematous, scaling plaques that progress to atrophy, scarring, pigmentary changes and irreversible destruction of the hair follicles.
Venous lake
An acquired benign vascular lesion, usually presenting as a soft, compressible, blue-purple papule or small nodule with a smooth surface, most commonly found on the lower lip or the auricle.
Milia
Small, superficial epidermal cysts filled with keratin, presenting as whitish or yellowish papules that are firm, smooth and generally 1–2 mm in diameter.
Intradermal melanocytic nevus
A benign melanocytic lesion characterised by a raised papule or small nodule, usually symmetrical and well-defined, with a skin-coloured, pinkish or brownish appearance.
Solar lentigo
A benign, flat, well-defined hyperpigmented macule, ranging in colour from light to dark brown, generally uniform in appearance, located in areas of chronic sun exposure.
Traumatic fibroma
A benign reactive lesion of fibrous tissue, usually associated with trauma or chronic irritation of the oral mucosa. It presents as a well-defined, firm papule or nodule with a smooth surface and a colour similar to that of the adjacent mucosa or slightly pink.
Folliculitis
Inflammation or superficial infection of the hair follicle, characterised by papules and/or pustules centred on the follicle, usually surrounded by an erythematous halo. It may cause itching, a burning sensation or mild pain.
Common wart
A benign skin lesion caused by infection with the human papillomavirus (HPV), presenting as a papule or small hyperkeratotic nodule with a rough, irregular surface, often with disruption of the skin lines.
Tinea manuum
Dermatophytosis of the hand, generally characterised by dry scaling, hyperkeratosis and erythema of the palm and/or interdigital spaces, often with unilateral distribution. It may cause itching or a burning sensation and usually has a chronic or recurrent course.
Tinea cruris
Dermatophytosis of the inguinal folds characterised by well-defined erythematous plaques, usually annular or arc-shaped, with an active, scaling and sometimes raised peripheral rim, associated with central depigmentation.
Seborrhoeic keratosis
A very common benign skin lesion, characterised by a well-defined papule or plaque with a verrucous, keratotic or papillomatous surface, typically appearing as though it is ‘stuck’ to the skin.
Palmar exfoliative keratolysis
A benign, recurrent dermatosis characterised by superficial scaling of the palms, with rounded or irregular areas of detachment of the stratum corneum and the formation of a peripheral scaling collar.
Nail psoriasis
Nail changes associated with psoriasis, including pitting, onycholysis, subungual hyperkeratosis, thickening and changes in the colour of the nail plate. Yellowish or brownish patches and nail dystrophy of varying severity may occur.
Guttate psoriasis
An acute or subacute rash consisting of multiple small, erythematous, desquamative papules with a ‘teardrop’ appearance, distributed predominantly over the trunk and the proximal parts of the limbs.
Paronychia
Inflammation or infection of the periungual tissues, characterised by pain, erythema and oedema along the lateral or proximal nail fold. In its acute form, it may progress to a purulent collection or abscess, and is often triggered by minor trauma, cuticle manipulation, manicures, nail-biting or an ingrown nail.
Parapsoriasis
A chronic inflammatory dermatosis characterised by fine, erythematous macules or plaques that are slightly scaly, predominantly located on the trunk and the proximal regions of the limbs. The lesions are usually asymptomatic or slightly pruritic; they may take on a brownish hue and exhibit a multifocal or symmetrical distribution.
PUPPP (Pruritic Urticarial Papules and Plaques of Pregnancy)
Pregnancy-specific pruritic dermatosis, also known as polymorphic eruption of pregnancy, characterised by erythematous papules that typically appear on abdominal stretch marks and may coalesce to form urticarial plaques.
Onycholysis
Distal or lateral detachment of the nail plate from the nail bed, resulting in a whitish, yellowish or opaque area beneath the nail. It may be asymptomatic or cause discomfort, particularly when extensive or associated with secondary inflammation.
Onychogryphosis
Chronic nail dystrophy characterised by marked thickening of the nail plate, increased length and progressive curvature, often taking on a ‘claw-like’ or ‘horn-like’ appearance.
Bouchard’s nodule
Bony prominences of the proximal interphalangeal joints of the fingers, typical of osteoarthritis of the hands. This results from bone remodelling and the formation of osteophytes, and may be asymptomatic or associated with mechanical pain, stiffness and functional limitation.
Papillomatous nevus
A benign melanocytic naevus characterised by a raised, well-defined papule or nodule with a papillomatous, cerebellar or verrucous surface. It may be skin-coloured, pink or brownish in colour and is usually asymptomatic.
Digital clubbing
Bulbous enlargement of the distal phalanges associated with increased convexity and curvature of the nails, producing the classic ‘drumstick’ appearance. It is generally bilateral and symmetrical; whilst it may occur in isolation, it is frequently associated with pulmonary, cardiovascular, neoplastic, gastrointestinal or hepatic disorders.
Eccrine hydrocystoma
A benign cystic lesion of eccrine origin, characterised by a small, translucent papule, skin-coloured or bluish in appearance, with a smooth surface and a cystic consistency.
Boil
A deep infection of the hair follicle, usually bacterial, characterised by an erythematous, warm and painful nodule, which may progress to the formation of a central purulent collection and spontaneous drainage.
Soft fibroma
A benign skin lesion, also known as an acrochordon, characterised by a papule or small, soft nodule, usually pedunculated, which is skin-coloured or slightly brownish.
Abdominal stretch marks
Linear atrophic lesions of the dermis, initially erythematous or purplish (striae rubra) and subsequently paler, hypopigmented and depressed (striae alba). They are often arranged in parallel lines and appear in areas subject to skin stretching, such as the abdomen, thighs and breasts.
Favre-Racouchot’s disease
A dermatosis associated with chronic photodamage, characterised by multiple open comedones, cysts and papules/nodules on thickened, elastotic skin, predominantly in the periorbital and malar regions.
Bowen’s disease
Squamous cell carcinoma in situ characterised by a well-defined, persistent, slow-growing erythematous or erythematous-brownish patch, usually with a scaling, crusted or hyperkeratotic surface.
Synovial cyst
A benign cystic lesion, usually filled with a gelatinous fluid rich in mucin, which originates near a joint or tendon sheath. It presents as a smooth, well-defined subcutaneous mass with an elastic or firm consistency, most commonly on the back of the wrist.
Digital mucous cyst
A benign periungual cyst, usually located near the distal interphalangeal joint, presenting as a papule or a small translucent or slightly bluish nodule. It may communicate with the joint and is frequently associated with osteoarthritis and osteophytes.
Epidermoid (sebaceous) cyst
A benign epidermoid cyst, usually presenting as a well-defined, mobile and slow-growing subcutaneous nodule, often with a visible central punctum. It is filled with keratinous material and is mainly found on the trunk, face and neck.
Interdigital candidiasis
Candida intertrigo occurring in the interdigital spaces, characterised by erythema, maceration, fissures and, at times, exudation. It may be associated with itching, a burning sensation or pain, particularly where fissures are present.
Atrophy of the thenar eminence
A reduction in muscle volume of the thenar eminence, resulting in a visible flattening or depression at the base of the thumb. This reflects a loss of mass in the thenar muscles, which are predominantly innervated by the median nerve, and may occur in chronic median neuropathy, particularly in advanced carpal tunnel syndrome.
Fordyce’s angiokeratoma
Benign vascular papules, usually multiple, dark red, purplish or black in colour, located mainly on the scrotum and, less frequently, on the vulva. They may have a smooth or hyperkeratotic surface.
Dacryocystitis
Acute infection of the lacrimal sac, usually associated with obstruction of the nasolacrimal duct, characterised by pain, erythema and swelling in the area below and to the medial side of the inner corner of the eye.
Lipoma
A benign tumour of adipose tissue, usually presenting as a well-defined subcutaneous mass that is soft, elastic and mobile in relation to the deeper planes. It is usually painless and slow-growing, but may cause mechanical discomfort when large or located in areas subject to pressure.
Periapical abscess
An odontogenic infection localised in the periapical region of a tooth, usually secondary to pulp necrosis caused by caries, trauma or periodontal disease. It is characterised by severe dental pain, often throbbing and aggravated by chewing, associated with tooth sensitivity and swelling of the adjacent gums.
Dental abscess
A suppurative infection of odontogenic origin, associated with a tooth or the periodontal tissues, characterised by severe pain, swelling of the gums and the formation of a purulent collection.
Melasma
Acquired hyperpigmentation characterised by brownish macules and patches, with irregular but generally well-defined borders, distributed symmetrically across the face. It is most common in the malar, frontal, mid-face and supralabial regions.
Tinea pedis
Dermatophytosis of the foot characterised by scaling, maceration and fissures, particularly in the interdigital spaces, often associated with itching, a burning sensation or discomfort. It may extend to the sole and lateral sides of the foot, sometimes taking on a diffuse hyperkeratotic ‘moccasin’ pattern.
Neonatal jaundice
A yellowish discolouration of the skin and sclerae in the newborn, caused by elevated serum bilirubin levels. It usually first becomes visible on the face and progresses in a craniocaudal direction towards the trunk and limbs as hyperbilirubinaemia increases.
Pityriasis versicolor
A superficial fungal infection caused by Malassezia, characterised by multiple hypo- or hyperpigmented macules, usually with fine, subtle scaling, predominantly affecting the trunk, neck and shoulders.
Hordeolum (stye)
An acute infection of an eyelid gland, usually caused by Staphylococcus, presenting as an erythematous, swollen and painful papule or nodule near the eyelid margin.
Nodular basal cell carcinoma
Basal cell carcinoma characterised by a slow-growing papule or nodule, usually translucent or pearly in appearance, with a smooth surface and tree-like telangiectasias.
Palmar dyshidrosis
Recurrent vesicular dermatosis of the hands, characterised by small, deep vesicles that are extremely itchy, located mainly on the palms and the sides of the fingers. The vesicles may coalesce and, following the acute phase, progress to desquamation, dryness and fissures.
Haematoma
Extravascular haemorrhage into the tissues, usually secondary to trauma, presenting as a swelling or a purplish, bluish or ecchymotic area, which is often painful on palpation.
Subungual haematoma
Blood collection beneath the nail plate, usually secondary to acute trauma or repeated microtrauma. It presents as a purplish, brownish or black area beneath the nail, often associated with throbbing or severe pain due to increased subungual pressure.
Subconjunctival haemorrhage
Haemorrhage beneath the bulbar conjunctiva, presenting as a bright red, uniform and well-defined area on the sclera. It is usually painless, does not cause photophobia or any change in visual acuity, and has a self-limiting course, with a gradual change in colour until it is reabsorbed.
Herpes simplex
Mucocutaneous infection caused by the herpes simplex virus (HSV-1 or HSV-2), characterised by small, clustered vesicles on an erythematous base, often preceded by pain, a burning sensation, paraesthesia or a stinging sensation.
Herpes labialis
A recurrent infection caused by the herpes simplex virus, usually HSV-1, characterised by small clusters of vesicles on an erythematous base in the lip or perioral region. It is often preceded by prodromal symptoms such as a burning sensation, tingling or localised pain.
Non-bullous impetigo
A superficial bacterial skin infection, usually caused by Staphylococcus aureus and/or Streptococcus pyogenes, characterised by fragile vesicles or pustules that rupture, giving rise to erosions covered by yellowish, honey-coloured scabs.
Melanonychia
Longitudinal pigmentation of the nail plate, usually brown to black in colour, resulting from the deposition of melanin in the nail. It may be physiological or benign, associated with melanocytic activation, a nail matrix naevus, medication or ethnic variations, but it may also be a manifestation of subungual melanoma.
Pterygium
A benign fibrovascular growth of the bulbar conjunctiva extending towards the cornea, usually triangular in shape and located in the nasal sector. It is associated with chronic exposure to ultraviolet radiation, wind, dust and environmental irritants.
Molluscum contagiosum
A benign skin infection caused by the molluscum contagiosum virus, a poxvirus, characterised by small, firm, smooth, pearly or skin-coloured papules, typically with central umbilication.
Infantile haemangioma
A benign vascular tumour of childhood, usually absent or barely noticeable at birth, which appears in the first few weeks of life and undergoes a phase of rapid proliferation in the first few months, followed by stabilisation and progressive regression over the years.
Granuloma annulare
A benign inflammatory dermatosis characterised by firm, smooth, skin-coloured or slightly erythematous papules, arranged in a ring or arc, usually without superficial scaling.
Neonatal acne
A benign dermatosis of the neonatal period characterised by small erythematous papules and pustules, predominantly on the face, particularly on the cheeks, forehead and chin, usually without comedones.
Xanthelasma
Benign cutaneous lipid deposits that present as yellowish plaques or papules, which are flat or slightly raised, with a smooth surface and soft consistency, located mainly on the eyelids, often bilaterally and symmetrically near the medial corner.
Chloronychia
Green to greenish-black discolouration of the nail plate, usually caused by colonisation or infection with *Pseudomonas aeruginosa*, often on a nail that has previously become detached or been traumatised.
Blepharitis
Chronic or recurrent inflammation of the eyelid margin, characterised by erythema, scaling and crusting at the base of the eyelashes. It may be associated with itching, a burning sensation, a foreign body sensation, tearing and eye irritation.
Dupuytren’s disease
A benign, progressive palmar fibromatosis characterised by the formation of nodules and fibrous strands in the palmar fascia, which may progress to flexion contracture of the fingers.
Shingles
Reactivation of the varicella-zoster virus characterised by clusters of vesicles on an erythematous base, distributed along one or more dermatomes, typically on one side of the body and without crossing the midline.
Erythema migrans
A skin lesion typical of Lyme disease, presenting as an erythematous macule or plaque that gradually increases in diameter over the course of several days, usually starting at the site of the tick bite.
Nummular eczema
An inflammatory dermatitis characterised by well-defined, round or oval erythematous plaques with a ‘coin-like’ appearance, which are often scaly and sometimes exudative or crusted.
Compound melanocytic nevus
A benign melanocytic naevus characterised by a papule or small, slightly raised nodule, usually symmetrical, well-defined and of a uniform brown colour or skin-coloured.
Bacterial conjunctivitis
Acute conjunctivitis of bacterial aetiology, characterised by conjunctival hyperaemia and mucopurulent or purulent discharge, often with the eyelids sticking together upon waking.
Vitiligo
An acquired condition characterised by the functional loss of melanocytes, manifesting as well-defined, achromic macules or plaques with a normal surface and no scaling.
Pityriasis alba
A benign and common skin condition in childhood, characterised by hypopigmented macules or plaques with poorly defined borders, a dry surface and mild, fine scaling. It is most common on the face, particularly around the cheeks, but may also affect the arms and trunk.
Angular cheilitis
Inflammation of the corners of the mouth characterised by erythema, fissures, maceration and, sometimes, scabs or exudate. It may cause pain, a burning sensation or discomfort when opening the mouth.
Sacrococcygeal cyst
Chronic pilonidal disease of the sacrococcygeal region, usually located in the midline of the intergluteal cleft, characterised by small skin orifices, sinus tracts or an inflamed nodule, often containing hair.
Venous ulcer
A chronic skin ulcer secondary to venous insufficiency, typically located in the distal region of the leg, particularly near the medial malleolus. It has irregular edges and a generally superficial, exudative bed; oedema, haemosiderin-induced hyperpigmentation, stasis dermatitis and lipodermatosclerosis may also be present.
Nasal vestibulitis
A bacterial infection of the nasal vestibule, usually caused by Staphylococcus aureus, characterised by erythema, pain, tenderness and the formation of papules, pustules, fissures or scabs at the entrance to the nostrils.
Erysipelas
An acute bacterial infection of the superficial dermis and cutaneous lymphatic vessels, usually caused by streptococci, characterised by an erythematous, warm, oedematous and painful plaque with well-defined, often slightly raised edges.
Senile purpura
A benign purpura associated with skin ageing and chronic photodamage, characterised by irregular purplish ecchymoses that appear spontaneously or following minor trauma, particularly on the backs of the hands and forearms.
The characteristics presented correspond to common clinical patterns and may vary between different presentations of the same condition. DxVisual is a differential diagnosis support tool and does not replace clinical assessment.
06/09/2026