ABSTRACT
Dermatomyositis is an autoimmune disease whose symptoms can be cutaneous, muscular, or systemic. Scalp involvement and non-scarring alopecia are common. Seborrheic dermatitis (SD) is a chronic relapsing inflammatory skin disorder with a predilection for areas rich in sebaceous glands, namely scalp, nasolabial folds, ears, eyebrows, and chest. SD etiology is not completely known, but it seems that skin colonization with harmless yeast called Malassezia is implicated. Psoriasis is a chronic, immune-mediated, inflammatory disease. There are five subtypes of psoriasis: vulgaris, guttate, pustular, inverse, and erythrodermic. Dermoscopic evaluation of scalp psoriasis shows decreased hair density, increased vellus hairs, diffuse white scales, signet ring vessels, structureless red areas, and hidden hairs. Syphilis is a sexually transmitted infection caused by the bacteria Treponema pallidum. Incidence rates of syphilis have increased substantially around the world, mostly affecting men who have sex with men and people infected with HIV. It is transmitted through direct contact with the infected mucosal lesion.
