A 49‐year‐old mestizo Mexican woman, who had suffered with asthma for 30 years, presented with a 6‐week history of fever, hyaline rhinorrea, myalgias, and arthralgias, with thoracic pain in the right apical and retrosternal region and dyspnea with little effort, without response to antimicrobials or bronchodilators. Four weeks previously, she had developed three painful urticarial plaques on the right thigh and genital region, accompanied by paresthesia in the same extremity. These correlated with the remission of asthma.
Physical examination demonstrated three erythematous and edematous plaques, measuring from 1.5 cm to 20 cm, with ill‐defined borders (Fig. 1), on the inner side of the right thigh, inguinal and crural regions. Laboratory tests showed a hemoglobin level of 14 g/dL, a hematocrit of 44%, leukocytes of 8003/mm^3^, eosinophils of 2020/mm^3^ (25.2%), platelets of 244,000/mm^3^, an erythrocyte sedimentation rate of 80 mm/h, and immunoglobulin E (IgE) elevated to 224 U/mL. Urinalysis, complement, and antinuclear antibody tests were normal or negative. Chest roentgenogram showed a micronodular infiltrate in the right apex and inferior lobe; X‐rays of the paranasal sinuses were normal. A biopsy of the skin demonstrated an infiltration in the dermis with a predominance of eosinophils infiltrating the vascular walls (Fig. 2). There were no granulomas.
Erythematous and edematous urticaria‐like plaques on the thigh
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Perivascular infiltrate with predominantly eosinophils and lymphocytes with degenerated collagen fibers
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She showed a good response to oral corticosteroids, with total remission of symptoms and normalization of the eosinophil count and IgE levels.