Skin Infections And Infestations

Infections and Infestations of the skin are most frequently convoyed by a rash and itching. Both Infections and Infestations are covenanted by direct close contact with another infected/infested being. Infections are caused by a bacterium, virus, or fungus. Infestations are caused by lice and scabies and fleas. Signs of bacterial infection emerge after the organisms have been introduced by dermis. Some organisms, such as staphylococci and streptococci, produce a pustular infection in which the main features are acute inflammation and the accumulation of huge numbers of white blood cells as pus. Other organisms, involving mycobacterium tuberculosis and treponema pallidum, may cause more chronic inflammatory variations without pus but including a characteristic arrangement of mononuclear inflammatory cells known histiocytes.

A number of dissimilar viral species are epidermotropic; that is, they assault the epidermis, from the skin surface through a slight abrasion, also as in viral warts, or from the bloodstream (viremia), as in varicella (chickenpox), or through the peripheral sensory nerves, as in herpes zoster (shingles). The human wart virus causes epidermal cellular proliferation and hyperkeratosis. When it forays the genital skin and mucous membranes, it produces moist, exuberant, vascular warts called condylomata acuminata. These warts are transmitted through contact and may become cancerous. Viral warts on non-mucosal surfaces occur in almost all children, although most vanish spontaneously with the development of obtained immunity.

Herpes simplex (cold sores, fever blisters) and herpes zoster (shingles) are two epidermal viral infections which forms blisters within the epidermis. The severity of these infections is influenced by the situation of the person’s immune system; they are more severe in injured persons, in the elderly, and in debilitated patients, especially those with cancer of the lymphoid system. The same virus causes herpes zoster (shingles) and varicella (chickenpox), and patients with shingles have previously had chickenpox. Some species of dermatophyte fungi may live on the dead horny layer of the skin. The inflammatory alters they produce are partly due to irritant products of the fungus, which disperse into the skin and partly to an immunologic reaction by the host in an try to eliminate the fungus.

Yeasts, of which Candida albicans is the most common, are also a cause of chronic skin or mucous membrane infection. Skin infestations are normal in persons living or working in overfull, unhygienic conditions. Pediculosis (crabs, lice, nits), which involves hairy areas, is analyzed by identifying the egg capsules (nits) that are covered to the hair shaft. Lice may also be apparent near the base of the hair. Scalp, alar, or pubic hair may be affected. Scabies, which is caused by the mite sarcoptes scabiei, is generally acquired through close personal contact. It affects all areas of the body except the soles of the feet, head, and neck and causes an itchy rash which is mainly an allergic reaction to the products of the mites.