Multiple keratoacanthomas arising post-UVB therapy.
BACKGROUND
Ultraviolet (UV) radiation is known to be an important etiologic agent in the development of skin cancer. Keratoacanthoma is an unusual, well-described cutaneous neoplasm that resembles squamous cell carcinoma but spontaneously resolves. Rarely, multiple keratoacanthomas may develop.


OBJECTIVE
We present a case of multiple keratoacanthomas in a patient with psoriasis who had received UVB phototherapy. These lesions were hyperkeratotic papules, many of which spontaneously resolved and demonstrated the histologic characteristics of keratoacanthoma.


CONCLUSIONS
We believe that UV radiation is the most likely etiologic factor in this patient's development of multiple keratoacanthomas. We wish to bring to the attention of clinicians this unusual adverse effect of UV treatment.
Craddock
Kenneth J
KJ
Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada.
Rao
Jaggi
J
Lauzon
Gilles J
GJ
Tron
Victor A
VA
D000368:Aged; D006801:Humans; D007636:Keratoacanthoma / Q000209:etiology*; D008297:Male; D011565:Psoriasis / Q000628:therapy; D012871:Skin Diseases / Q000209:etiology*; D014467:Ultraviolet Therapy / Q000009:adverse effects*