8 yo boy with lesion on wrist

History: The patient is an 8 yo boy with a one week history of an expanding lesion on the right wrist. He plays in a sandbox that is frequented by stray cats. He's been using clotrimazole cream for three days.

Physical Exam: There is a 2 cm diameter plaque on the right wrist. The periphery appears to be vesicular and possibly a bit scaly. No other lesions.

Lab: KOH equivocal - hard to interpret because of cream artifact.

Diagnosis: ? Kerion of glabrfous skin.

I plan to stop the cream, repeat KOH in a few days and have obtained a fungal culture. Will biopsy if still uncertain and process is progressing.



Follow-up of Jan 3, 2005. The patient was seen again and the KOH prep repeated. Today, this was markedly positive (no cream artifact) Dx: Kerion of Glabrous Skin. Usually caused by M. canis. See below for references.




2.5 cm lesion right wrist 



References:

1: Alteras I, Feuerman EJ, David M, Segal R.

The increasing role of Microsporum canis in the variety of dermatophytic

manifestations reported from Israel.

Mycopathologia. 1986 Aug;95(2):105-7.

PMID: 3762660 [PubMed - indexed for MEDLINE]



2: Powell FC, Muller SA.

Kerion of the glabrous skin.

J Am Acad Dermatol. 1982 Oct;7(4):490-4.

PMID: 6216270 [PubMed - indexed for MEDLINE]