Non-bullous impetigo
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- Localization. Face
- Erythematous lesion? Erythematous lesion
- Evolution time. Acute: less than 2 weeks
- Skin lesion. With fluid: vesicle, blister or pustule
- Surface texture. Crust/ulceration/excoriation
- Edges Poorly defined
- Color. Other colors: orange, yellow, gray
- Distribution of lesions. Confluent/coalescent lesions
- Associated symptoms. Itching
- Additional information.
Brief information
- Impetigo is a common infection of the superficial layers of the epidermis, highly contagious and most commonly caused by gram-positive bacteria: Staphylococcus aureus and Streptococcus pyogenes (alone or together).
- There are two presentations of impetigo: nonbullous (also known as contagious impetigo) and bullous.
- Non-bullous impetigo is the most common form of presentation, comprising 70% of cases.
- It can be further classified as primary (bacterial invasion of intact skin) or, more commonly, secondary (as a result of minor trauma that breaks the skin barrier).
- Non-bullous impetigo is the most common form of presentation, comprising 70% of cases.
- Non-bullous impetigo typically manifests itself on the skin of the face (nostrils, perioral region and extremities). It is characterized by the sequence:
- Maculopapular lesions that rapidly evolve into thin-walled vesicles;
- Rupture of the vesicles leaving superficial erosions, sometimes itchy or painful, covered by honey-colored crusts;
- The course of the infection can last 2 to 3 weeks if left untreated. Does not leave a scar;
- Regional lymphadenitis may occur, but systemic symptoms are unlikely.
- It is most prevalent in children aged 2 to 5 years, but can occur at any age.
- The peak incidence occurs during summer and autumn.
- More common in hot and humid climates.
- In children under 2 years of age, it usually manifests as bullous impetigo.
- It is generally a self-limiting condition with no complications.
- However, up to 5% of users with non-bullous impetigo may develop post-streptococcal glomerulonephritis:
- Renal dysfunction appears 7 to 14 days after infection.
- Transient hematuria and proteinuria may last a few weeks or months.
- It is unknown whether antibiotic therapy has any effect on preventing the development of this condition.
- Other rare complications include: septic arthritis, scarlet fever, sepsis and staphylococcal scalded skin syndrome.
- However, up to 5% of users with non-bullous impetigo may develop post-streptococcal glomerulonephritis:
Differential diagnosis
- Atopic dermatitis
- Scabies
- Contact dermatitis
- Herpes simplex
- Candidiasis
- Varicella zoster
Treatment
- Topical treatment. Consider in the case of:
-
- Localized non-bullous impetigo (maximum of 5 lesions on a single area of skin)
- Adults and children
- Clean with soap and water before applying the topical agent.
- Reevaluate after 3 days. If no response, switch to oral antibiotic therapy.
- Options include:
- Fusidic acid 2%, 8/8h, 5-7 days; or
- Mupirocin 2%, 8/8 hours, 5-7 days.
-
- Oral treatment. Consider in the case of:
-
- Extensive non-bullous impetigo (more than 5 lesions or impetigo involving more than one area of the skin);
- Bullous impetigo;
- Ecthyma;
- Impetigo with abscess;
- Immunocompromised user;
- Failed topical treatment.
- Adults
- 1st line
- Flucloxacillin 500mg, oral, every 6 hours, 7 days.
- 2nd line
- Amoxicillin + ac. clav. 500mg +125mg, oral, 8/8h, 7 days; or
- Clindamycin 300-450mg, oral, 6/6h or 8/8h, 7 days; or
- Doxycycline 100mg, oral, every 12h, 7 days; or
- Sulfamethoxazole + Trimethoprim 800mg+160mg, 12/12h, 7 days.
- 1st line
- Child
- 1st line
- Flucloxacillin 50-100 mg/kg/day, (max. 1500-2000mg/day), 6/6h, 7 days.
- 2nd line
- Amoxicillin + ac. clav. 40-50 mg/kg/day, (max. 1500mg/day), 8/8h, 5-7 days; or
- Clindamycin at 30-40 mg/kg/day (max. 1800mg/day), 6/6h or 8/8h, 5-7 days; or
- Sulfamethoxazole + Trimethoprim 10 mg/kg/day, (max. 160mg/day), 12/12h, 5-7 days.
- 1st line
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https://www.aafp.org/pubs/afp/issues/2014/0815/p229.html
https://www.ncbi.nlm.nih.gov/books/NBK430974/