PT  - JOURNAL ARTICLE
AU  - Marc Schindewolf
AU  - Svantje Schwaner
AU  - Manfred Wolter
AU  - Hartmut Kroll
AU  - Andreas Recke
AU  - Roland Kaufmann
AU  - Wolf-Henning Boehncke
AU  - Edelgard Lindhoff-Last
AU  - Ralf J. Ludwig
TI  - Incidence and causes of heparin-induced skin lesions
AID  - 10.1503/cmaj.081729
DP  - 2009 Oct 13
TA  - Canadian Medical Association Journal
PG  - 477--481
VI  - 181
IP  - 8
4099  - http://www.cmaj.ca/content/181/8/477.short
4100  - http://www.cmaj.ca/content/181/8/477.full
SO  - CMAJ2009 Oct 13; 181
AB  - Background: Little is known about the incidence and causes of heparin-induced skin lesions. The 2 most commonly reported causes of heparin-induced skin lesions are immune-mediated heparin-induced thrombocytopenia and delayed-type hypersensitivity reactions. Methods: We prospectively examined consecutive patients who received subcutaneous heparin (most often enoxaparin or nadroparin) for the presence of heparin-induced skin lesions. If such lesions were identified, we performed a skin biopsy, platelet count measurements, and antiplatelet-factor 4 antibody and allergy testing. Results: We enrolled 320 patients. In total, 24 patients (7.5%, 95% confidence interval [CI] 4.7%–10.6%) had heparin-induced skin lesions. Delayed-type hypersensitivity reactions were identified as the cause in all 24 patients. One patient with histopathologic evidence of delayed-type hypersensitivity tested positive for antiplatelet-factor 4 antibodies. We identified the following risk factors for heparin-induced skin lesions: a body mass index greater than 25 (odds ratio [OR] 4.6, 95% CI 1.7–15.3), duration of heparin therapy longer than 9 days (OR 5.9, 95% CI 1.9–26.3) and female sex (OR 3.0, 95% CI 1.1–8.8). Interpretation: Heparin-induced skin lesions are relatively common, have identifiable risk factors and are commonly caused by a delayed-type hypersensitivity reaction (type IV allergic response). (ClinicalTrials.gov trial register no. NCT00510432.)