Volume 21 Number 12 December 2015 Case presentation Eosinophilic dermatitis of hematologic malignancy

Lauren Penn, Ian Ahern, Adnan Mir, Shane Meehan
Eosinophilic dermatosis of hematologic malignancy is a rare, paraneoplastic phenomenon that presents as a pruritic papular or vesicular eruption that is clinically and histopathologically similar to insect bites. We present a 56-year-old man with multiple relapses of diffuse large B cell lymphoma with a typical presentation of pruritic papules and vesicles on the extremities that correlate with a recent relapse of his lymphoma. Case synopsis History: A 56-year-old man with multiple relapses of
more » ... ltiple relapses of diffuse large B cell lymphoma, which was diagnosed in 2012, presented to the Skin and Cancer Unit for evaluation of a pruritic, papular eruption on the upper and lower extremities. The lesions first developed a week after his first cycle of chemotherapy with rituximab and bendamustine. He had noted similar eruptions prior to previous relapses of his lymphoma, which improve with treatment of his malignant condition. He describes the lesions as initially large and edematous with associated pain and burning before evolving into small, firm, pruritic papules. The patient declined a biopsy and triamcinolone ointment 0.1% was prescribed. The patient returned for a follow up visit three weeks later stating that his eruption had appreciably improved. He felt that the triamcinolone ointment helped somewhat but attributed much of his improvement to his second round of chemotherapy, which had occurred 12 days prior. A punch biopsy of a residual lesion on the right thigh was performed, which demonstrated findings that were most consistent with a resolving eczematous dermatitis. One month later, the patient returned with an exacerbation of his skin lesions, which now involved vesicles over the palmar surfaces of the hands. Punch biopsies of representative lesions on the left hypothenar eminence and left forearm were performed. Our patient has responded to a combination of antihistamines, topical glucocorticoids under occlusion, and intralesional glucocorticoids. Physical examination: On the arms, legs, and dorsal aspects of the hands, there were small, pink papules. Within the web space of the first and second fingers of the left hand and over the hypothenar eminences there were tense, minimally elevated vesicles with no surrounding erythema, which measured 2-to-5-mm in diameter. Laboratory data: A complete blood count showed eosinophils of 8% and basophils of 2%. A complete metabolic panel and lactate dehydrogenase were normal. Histopathology: There is a superficial and deep, predominantly perivascular infiltrate of lymphocytes and innumerable eosinophils. There is slight epidermal hyperplasia, spongiosis, and parakeratosis. A periodic acid-Schiff stain with diastase fails to show fungal elements.