Schindewolf M, et al. - Researchers performed this prospective cohort study including major orthopedic surgery patients, to determine the incidence and causes of heparin-induced skin lesions in these subjects. Using further diagnostics [skin biopsy, clinical/laboratory assessment for thrombosis, bleeding, heparin-induced thrombocytopenia (HIT), cross-allergies], they examined the cutaneous adverse impacts in patients with subcutaneous low-molecular-weight heparin (LMWH) treatment. They found that during LMWH treatment, these patients showed a low risk for heparin-induced skin lesions, unlike non-surgical patients. A delayed-type hypersensitivity reaction (DTH) reaction accounted for all lesions. Between individual patient cohorts, a considerable difference was evident in the risk for DTH. No link with HIT was reported.