[Giant blister due to cutaneous larva migrans].

count of 41 × 103/mm3. Isotretinoin therapy was suspended and new treatment was instated with 100 mg/d prednisone; oral contraceptive medication was maintained. After 9 days, the platelet count had returned to normal (179 × 103/mm3) and prednisone was suspended. The Coombs test and tests for antinuclear antibodies, anticardiolipin, human immunodeficiency virus, hepatitis B and hepatitis C virus, rheumatoid factor, antistreptolysin O, and antiplatelet antibodies were negative. The platelet count remained normal 18 months later. Isotretinoin has been shown to cause a long list of secondary effects, including thrombocytopenia, of which only 4 cases have been previously reported.1-4 The test for antiplatelet antibodies is usually positive in thrombocytopenia induced by isotretinoin.6 This test was negative in our patient, suggesting that the process was mediated by nonimmunologic mechanisms. We cannot rule out the implication of the oral contraceptives in this case, though we believe it to be improbable.