Cutaneous Lymphoid Hyperplasia (Lymphocytoma Cutis, Lymphadenosis Benigna Cutis, Pseudolymphoma) Benign cutaneous lymphoid hyperplasia can be caused by medications, injected foreign substances, infections, and arthropod bites, or it may be idiopathic….
Melanocytes originate in the embryonal neural crest and migrate to the epidermis, dermis, leptomeninges, retina, mucous membrane epithelium, inner ear, cochlea, and vestibular system. Nevus cells are a form of…
Granulatomatous reactions generally represent patterns of chronic inflammation that may take a long time to develop and a long time to respond to treatment. Granulomatous inflammation can occur in the…
Lupus erythematosus (LE), dermatomyositis (DM), scleroderma, rheumatoid arthritis, Sjögren syndrome, eosinophilic fasciitis, relapsing polychondritis, and related disorders are classified as connective tissue diseases. Basic to all these is a complex…
Syphilis Syphilis, also known as lues, is a contagious, sexually transmitted disease caused by the spirochete Treponema pallidum subspecies pallidum. The only known host is the human. The spirochete enters…
Tuberculosis No ideal classification scheme exists for cutaneous tuberculosis (TB), but the system listed here is logical and takes into account the mechanism of disease acquisition. Unfortunately, unlike in Hansen…
Lichen Planus Lichen planus (LP) is a common, pruritic, inflammatory disease of the skin, mucous membranes, and hair follicles. It occurs throughout the world, in all races. Cutaneous LP affects…
Contact Dermatitis There are two types of dermatitis caused by substances coming in contact with the skin: irritant dermatitis and allergic contact dermatitis. Irritant dermatitis is an inflammatory reaction in…
Flushing Flushing presents with transient erythema, usually localized to the face, neck, and upper trunk, and a sensation of warmth. Flushing may be physiologic or pathologic; though normally benign, causes…
