Case of Eosinophilia Induced by Etretinate

Abstract

Case of Eosinophilia Induced by EtretinateTo the Editor.\p=m-\The cutaneous side effects of etretinate are now well known, the most common being dryness of the mucosa, alopecia, palmoplantar hyperkeratosis, and pruritus.1,2 Certain metabolic abnormalities are also relatively common, such as the induction of hypertriglyceridemia and hypercholesterolemia as well as enzyme alterations, mainly of the transaminases and alkaline phosphatase.3,4 Moreover, etretinate therapy, like any other drug therapy, may be accompanied by allergic reactions and/or idiosyncratic effects.A case of hypersensitivity to etretinate therapy, marked by hyperpyrexia, eosinophilia, and hepatotoxic reaction, has recently been described.4 An example of suspected hypersensitivity to etretinate therapy is reported in this communication.Report of a Case.\p=m-\A71-year-old man was admitted for erythroderma of about two years' duration that was resistant to various attempts at treatment, including etretinate therapy, which had been received by the patient at irregular intervals for about two months. There was no evidence of familial or personal predisposition. The blood chemistry results disclosed neither enzyme alterations nor changes in the lipid metabolism. The blood cell counts and hematocrit values were both normal.In particular, there was no evidence of eosinophilia (leukocyte count, 4.1 X lO'/L [4100/mmJ]; eosinophil count, 0.041 X 10VL [41/mm3]). The clinical diagnosis was psoria¬ sis. This was confirmed histologically. Treatment with etretinate commenced as follows: 75 mg/d for two weeks, followed by 50 mg/d, with periodic blood chemistry checks.A slight initial improvement (reduction of erythema and itching) was followed by the appearance of eosinophilia (1.86 X 10VL [1863/mm3]), with no changes in the other values on the 28th day, and even higher levels (6.328 X 10V L [6328/mm3]) subsequently. This increase was accompa¬ nied by a gradual exacerbation of the clinical picture, with pronounced erythema and the appearance of edema (par¬ ticularly on the lower limbs) and signs of exudation. Pruritus also returned. In the days prior to the peak in the eosinophilia count, hyperpyrexia appeared (maximum temperature, 39°C). All tests performed to establish the cause of the eosinophilia proved negative, ie, stool para¬ sites, paper radioimmunosorbent test, radioallergosorbent test, hemagglutination for echinococcus, and roentgenograms of the chest and digestive tract. Computed tomographic scan of the liver revealed a roundish formation in the left lobe. This was interpreted as a cavernous hemangioma following the computed tomographic scan. Microscopic examination of the bone marrow aspirate did not disclose any red blood cells or granulocyte atypia in the bone marrow. These negative findings pointed to an iatrogenic effect.Etretinate administration was, therefore, suspended, and corticosteroid therapy was started in the form of 25 mg/d of prednisone. There was an appreciable improve¬ ment in the patient's clinical picture after a few days, together ...