Skin Conditions due to physical agents

The physical agents which can affect the integument vary from friction, pressure and maceration to cold, heat, sun etc. They produce a large percentage of dermatoses seen in general practice; the majority of these dermatoses are minor problems, only a very small percentage is serious. Apart from the intensity and quality of the physical agents, the sensitivity and vitality of the individual also plays an important part in the bringing about of skin disorders.

FRICTION AND PRESSURE

Abrupt and intense friction or pressure produces erythema and sometimes, a blister.

A common example is the blister produced on the heel by tight shoes. Continuous light pressure or friction produces pigmentation which is commonly seen around the waist where the sari, pajama's string or the trouser belt is tied. If the belt or string is tightly tied over a long period, it will roughen the skin, even ulcerate it and result in depigmentation. Other examples of such irritation are the sites of the truss, corset, brassiere and the hat band.

AFFECTIONS DUE TO HEAT

Mild heat produces erythema due to the dilatation of blood vessels. Excessive dry heat produces various degrees of bums, and moist heat, scalds. They are mainly surgical conditions. Electric bums are deeper than they appear, and are generally slow in healing.

Mild degree of electrical bums is occasionally seen following the use of medical diathermy in people wearing metal embroidered saris.

Frequent application of mild heat to any part of the body results in pigmentation: It is found, for instance, on the legs of cooks, and on the abdomens of Kashmiri people using the kangri. This pigmentation is dark-brown in color, and occurs in a network fashion dependent upon the arterial and venous circulation of the blood. This condition is called ephelis ab igne.

Exposure to heat produces profuse sweating which may give rise to different types of miliaria or prickly heat.

AFFECTION DUE TO SUNLIGHT

Sunlight when mild stimulates the integument, but if fair skin is repeatedly exposed to it, over long periods, it will produce diffuse pigmentation or freckles (small, spotted pigmentation). Strong sunlight bums the integument; in hypersensitive individuals, certain light or sensitization dermatoses are produced.

Corn and Callus

Bunion

Cracking

Maceration

Acrocyanosis

Livedo reticularis

Frost bite

Solar dermatitis

Xeroderma pigmentosum

Solar eczema

Solar urticaria

Actinic reticuloid