A 24 year old male with a 3 week history of rash on his arms and legs, onset after completing a 2 week Hazmat training course where he spent multiple hours in a full hazmat suit in hot humid weather. He denies fevers or recent illness. States rash is mildly itchy and he has been applying over the counter Hydrocortisone 1% cream without improvement. What’s your diagnosis?
b. Contact Dermatitis
c. Lichen Simplex
d. Tinea Corporis
Answer d. Tinea Corporis
Tinea corporis also known as ringworm, is a superficial fungal infection (dermatophytosis). Tinea corporis may be acute with sudden onset and rapid spread, or can be chronic with a slow extension of a mildly inflamed rash. It usually affects exposed areas but may also spread from other infected sites. In the acute phase tinea corporis can present as itchy inflamed red patches and may be pustular.
The term ringworm refers to round or oval red scaly patches. The patches can be red and scaly in the middle or healed in the middle. Sometimes one ring arises inside another older ring and may be inflamed or non inflamed.
The differential diagnosis can include, psoriasis, contact dermatitis, lichen simplex, discoid eczema, pityriasis rosea, and impetigo.
Diagnosis and Treatment. The diagnosis of tinea corporis is confirmed by microscopy and culture of skin scrapings and treated with topical anti fungal agents. Oral anti fungal may be used if topical are unsuccessful.