A coal-tar based shampoo was prescribed. After the shampoo failed to improve the irritation his parents decided to cut his hair. However, he continued to scratch and developed widespread erythema, crusting and some areas of bleeding. Calamine had been applied to calm the irritation. No other family members had any similar skin lesions and the patient was well.
Diagnosis and management
A diagnosis of impetigo was made and the skin was swabbed. As the differential diagnosis was tinea capitis, hair was sent for microscopic examination. With a provisional diagnosis of a bacterial infection oral co-amoxiclav was prescribed. Impetigo is usually caused by staphylococcal or streptococcal infection, and may occur as a localised outbreak or a primary occurrence.
The swab revealed Staphylococcus aureus and microscopy and mycology was negative for fungal infection. The crusting settled, but required a 10-day course of antibiotics.
Possible differential diagnoses
- Tinea capitis.
- Head lice with secondary infection.
- Scalp psoriasis.
- Seborrhoeic dermatitis.
- Tinea capitis can present in a variety of ways from a superficial infection resembling dandruff to a severely inflamed deep abscess, known as a kerion.
- The condition is common in children.
- The fungus not only affects the epidermis but can also affect the hair follicles.
- Topical antifungal preparations are usually ineffective and oral antifungals, such as terbinafine, are required.
- Family members should be screened and treated if appropriate.
- Contributed by Dr Nigel Stollery, a GP in Kibworth, Leicestershire.