Wells' syndrome triggered by centipede bite.

Abstract

A 68-year-old African–American woman was awoken from her sleep by a centipede bite on the dorsum of her left hand. Several days later, the patient presented to the emergency room complaining of fevers, severe itching, swelling, and blistering (Fig. 1) of both hands. The past history was unremarkable. There was no history of asthma or use of medications. Physical examination at that time was consistent with a bullous cellulitis of the hands. Laboratory investigations revealed: white blood cell count (WBC), 10.3 (normal, 41, 2, 3-9, 10.5); differential: 54 neutrophils, 15 lymphocytes, and 31 eosinophils. The platelet count was 225,000/mm3. A blood chemistry profile was within normal limits. Blood cultures and stool examination for ova and parasites were negative. The patient was treated with oral cephalexin and diphenhydramine. Figure 1Open in figure viewerPowerPoint Left hand reveals a bulla and several vesicles at the site of the centipede bite Two weeks later the patient was seen in the dermatology clinic. She complained of unabated pruritus and extensive new lesions. Physical examination revealed a moderately obese woman with normal vital signs. Firm gray plaques with an irregular contour were present on the left hand. The buttocks (Fig. 2) and extensor aspects of her upper arms were strikingly indurated and had a blue–gray discoloration. Violaceous, indurated oval patches were noted on the medial aspect of both knees. Finally, a slate-colored, irregularly outlined plaque on the heel of the right foot was present. Complete blood count revealed: WBC, 16.5; differential, 8 neutrophils, 9 lymphocytes, 81 eosinophils, and 2 monocytes. The differential was repeated and confirmed. The platelet count was 568,000/mm3. Figure 2Open in figure viewerPowerPoint Blue–gray discoloration and induration of the buttocks as well as the proximal thighs is seen. These changes became apparent several weeks after the initial blistering reaction of the hands A skin biopsy from the patient's left upper arm revealed a superficial and deep perivascular dermatitis. In addition, the dermis had a dense inflammatory infiltrate consisting of numerous interstitial eosinophils, many of which were degranulated. Collagen bundles coated with eosinophilic granules characteristic of flame figures were abundant (Fig. 3). The changes were consistent with eosinophilic cellulitis. Chest X-ray revealed no evidence of infiltrates. Figure 3Open in figure viewerPowerPoint There is a dense infiltration of eosinophils in the dermis, many of which have degranulated. Several collagen bundles coated by an extracellular amorphous material (flame figures, arrow) are evident in the center (hematoxylin and eosin stain; original magnification, ×100) A course of oral corticosteroids was prescribed. One week later, the lesions were substantially less indurated, but otherwise similar in appearance. Complete blood count revealed: WBC, 9.9; differential: 21 neutrophils, 19 lymphocytes, 1 basophil, 51 eosinophils, and 8 monocytes. The platelet count was 408,000/mm3. Hematologic consultation was arranged for bone marrow biopsy and examination. Unfortunately, the patient did not return for subsequent appointments.