Low doses of low molecular weight heparin in vivo inhibits the elicitation of contact hypersensitivity.

Low-dose low molecular heparin inhibits T lymphocyte-mediated autoimmune disease and allograft reactions in mice in vivo and in vitro. High doses of heparin are not effective. The purpose of this preliminary study was to analyze the effect of low-dose, low molecular weight heparin (Enoxaparin, Clexane®) on the expression of patch testing in patients with contact dermatitis. Eleven patients with allergic contact dermatitis, and positive patch tests reactions, were given a single subcutaneous injection of Clexane® 3 mg (0.03 ml) and were reevaluated for positive reactions after the injection. Eight out of 21 positive reactions (38%) became negative after the injection and 4 out of 21 reactions (19%) changed from ++ before the injection to+ after