Impetigo

The causative organisms are mainly pyogenic staphylococci, less so streptococcus pyogenes; diminished local resistance leads to the development of this disease. Impetigo contagiosa can occur primarily as such, or secondarly, as a complicating factor in scabies, pediculoses, eczemas, seborrhoeic dermatitis and herpes simplex. To this second process we give the name, Impetiginization.

Impetigo contagiosa has a world-wide distribution. Though it can occur at any age, it is commonly a disease of childhood. Patients are usually undernourished or run down. Infection is transmitted by contact with any individual carrying pyogenic organisms, directly or through towels, handkerchiefs etc. The sites of predilection are the exposed regions of the body, especially the face and scalp; though it can occur on any part of the body. The incubation period is two to three days.

Clinical features of Impetigo

It starts as a superficial bulla containing seropurulent matter. The contents soon coagulate producing a thick, stuck-on, honey-colored crust. This characteristic crust is the most important diagnostic feature of impetigo. At the periphery of the crust may be seen the epidermal tags or the edge of the bulla.

The removal of the crust reveals moist, glistening surface with copious serous secretion which is infectious, to contiguous areas and to other persons. One or several lesions may be seen in one individual; usually, however, the lesions are multiple. Infection may spread to hair follicles in the scalp or beard region and set up folliculitis. In the tropics, bullous impetigo may even be seen in adults.