Aspects of skin biology pertinent to pharmacology

Diseases are clinically manifest as disturbances or distortions of normal cell form and/or function due to some etiologic influence. The etiology of only comparatively few diseases has been identified, and this has permitted development of pharmacologic materials that specifically attack the cause of disease (e.g., antibiotics) or that interfere with the etiologic agent exerting its adverse effects (e.g., sunscreens). Specific etiologies, however, are not known for most diseases. Hence, therapeutic materials available today are mostly drugs that either block the abnormal expressions of cell form or function manifest in the disease (e.g., corticosteroids) or exert inHuences re‐enforcing or enhancing expression of normal cell form or function (e.g., cancer immunotherapy). Despite the fact that most pharmacologic agents today do not attack cause of disease, their modification of disease expression constitutes effective therapy.