Statins: Novel Additions to the Dermatologic Arsenal?

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins), atorvastatin, cerivastatin, fluvastatin, pravastatin, lovastatin and simvastatin, reduce atherogenesis and cardiovascular morbidity. Besides, there is growing evidence that statins have immunomodulatory activities. Statins downregulate the expression of adhesion molecules, intercellular adhesion molecule-1 (ICAM-1), monocyte chemotactic protein-1 (MAC-1) and lymphocyte function-associated antigen-1 (LFA-1), on leucocytes and endothelial cells and, through binding to LFA-1, interfere with ICAM-1-LFA-1 interaction, which is crucial for activation of lymphocytes by antigen-presenting cells, ingress of leucocytes into the inflammation sites and immunologic cytotoxicity. Statins inhibit the inducible expression of major histocompatibility complex class II in several cell types including macrophages and downregulate the expression of T-helper-1 (Th1) chemokine receptors on T cells, leading further to inhibition of activation of lymphocytes and their infiltration into the inflammation sites. Statins block the induction of inducible nitric oxide synthase and the expression of several proinflammatory cytokines such as tumour necrosis factor-alpha and interferon-gamma in macrophages and possess antioxidant effects. These agents inhibit the proliferation of immunocytes and the activation of natural killer cells. Regarding the above facts and in view of their safety and inexpensiveness, statins may prove invaluable in the treatment of a multiplicity of dermatologic disorders, especially those characterized by ingress of activated leucocytes into the skin, such as alopecia areata, vitiligo, lichen planus, subacute cutaneous lupus erythematosus, erythema multiforme, psoriasis, bullous pemphigoid, systemic sclerosis, mycosis fungoides, toxic epidermal necrolysis and Behcet's disease.