Drugs and Wells' syndrome: a possible causal relationship?

Abstract

In April 1997, a 28‐year‐old woman presented with a 3‐day history of multiple papules and vesicles on the fingers and wrist of her right hand. She reported that she had been taking nonsteroidal anti‐inflammatory drugs containing tenoxicam and diclofenac sodium, and had no history of an insect bite. The medical history also included pruritic erythema on her trunk 1 month before her initial visit, and oral tenoxicam and diclofenac sodium treatment for ankle arthralgia 2 days before the skin lesions appeared. At that time, her dermatologist had told her that the skin lesions might be due to an insect bite and were secondarily infected. She took amoxicillin for the lesions, and during the following days developed bullous lesions on her hands and feet. The patient was diagnosed with ‘‘drug reaction’' at another hospital based on a histopathologic examination of the affected skin. Treatment with topical corticosteroids and oral antihistamines was ineffective.Physical examination revealed a few crusted, erythematous, papular lesions on the dorsal aspects of the patient's feet, bullous lesions on her right wrist, and vesiculopapules on her fingers. She had no fever or other abnormal clinical findings.Laboratory studies showed a white blood cell count of 6000/mL with 16.5% eosinophils. A bacterial culture of the content of one of the bullous lesions was negative. The results of stool tests for parasites and ova were negative. Clinical and laboratory findings were in line with the diagnosis of drug reaction. The patient was advised not to take nonsteroidal anti‐inflammatory drugs. The skin lesions resolved rapidly on treatment with wet compresses of Burow's solution and oral prednisolone (40 mg/day). The dose of prednisolone was gradually reduced, and was discontinued after 3 weeks. The patient was readmitted in July 1997 for an indurated, erythematous plaque on her left foot, a lesion that resembled cellulitis. Her history at that time included the initiation of amoxicillin treatment for a gingival abscess 2 days before the skin lesion appeared. The lesion regressed after amoxicillin was discontinued and the patient received an intramuscular injection of triamcinolone acetonide.Several months later, in October 1997, she developed a similar cellulitis‐like lesion on her right ankle. This time there was no history of drug intake. We obtained a skin biopsy from the lesion, and histopathology revealed an intense eosinophilic infiltrate in the dermis and extending into the subcutaneous tissue. Flame figures were abundant (Fig. 1). We also observed edema and erythrocyte extravasation in the dermis. Based on these features and her history, a diagnosis of Wells' syndrome was made. The skin lesion resolved spontaneously, and she has experienced no lesion recurrence since.A characteristic ‘‘flame figure’' (hematoxylin and eosin stain; original magnification, × 230)image