Syphilis, Yaws, Bejel, and Pinta
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…
Mycobacterial Diseases
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 and Related Conditions
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 and Drug Eruptions
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…
Erythema and Urticaria
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…
Pityriasis Rosea, Pityriasis Rubra Pilaris, and Other Papulosquamous and Hyperkeratotic Diseases
Pityriasis Rosea Clinical Features Pityriasis rosea is a mild inflammatory exanthem characterized by salmon-colored thin papules and plaques that are at first discrete but may become confluent ( Fig. 11.1…
Dermatoses Resulting From Physical Factors
The body requires a certain amount of heat, but beyond definite limits, insufficient or excessive amounts are injurious. The local action of excessive heat causes burns or scalds; undue cold…
Seborrheic Dermatitis, Psoriasis, Recalcitrant Palmoplantar Eruptions, Pustular Dermatitis, and Erythroderma
Seborrheic Dermatitis Clinical Features Seborrheic dermatitis is common, occurring in 2%–5% of the population. It is a chronic, superficial, inflammatory disease with a predilection for the scalp, eyebrows, eyelids, nasolabial…
