Cutaneous immediate and late phase reactions to schistosomin in schistosomiasis patients.

Cutaneous immediate and late phase reactions (LPR) to schistosomin were studied in 29 patients with schistosomiasis mansoni. In 12 of these patients, the determination of total and specific serum IgE by immunoenzymatic method against schistosome antigen was carried out using serum samples obtained on the same day as the cutaneous tests. Skin biopsies were taken from 4 typical LPRs. Immediate reactions occurred in all except one and LPRs in 12 (41.3%). Patients with positive cutaneous reactions had highe levels of specific serum IgE against schistosome antigen. Histopathological studies showed a moderate exudate consisting mainly of neutrophils (60%) and eosinophils (40%). LPRs in schistosomiasis have the same characteristics reported in the medical literature in relation to time of appearance, morphology and histopathology. The immunopathogenic role played by LPRs in the patients remains to be clarified.