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Definition: impetigo from Philip's Encyclopedia

Contagious skin condition caused by streptococcal or staphylococcal infection. It causes multiple, spreading lesions with yellowish-brown crusts.

Summary Article: Impetigo
From Black's Medical Dictionary, 43rd Edition

A contagious skin disease, more common in children, caused usually by Staphylococcus aureus and less often by Streptococcus pyogenes. The itching rash is seen especially on the face but may spread widely. Vesicles and pustules erupt and dry to form yellow-brown scabs. Untreated, the condition may last for weeks. In very young infants, large blisters may form (bullous impetigo).


Crusts can be gently removed with SALINE. Mild cases are likely to respond to frequent application of the antibiotic mupiricin into the nostrils or NEOMYCIN/BACITRACIN ointment; more severe cases might need to be treated with FLUCLOXACILLIN or one of the CEPHALOSPORINS. If the patient is allergic to penicillin, ERYTHROMYCIN can be used. Bactericidal soaps may also help.

For severe, intractable cases, an oral retinoid drug called isotretinoin (commercially produced as Roaccutane®) is sometimes prescribed. It acts mainly by suppressing SEBUM production in the sebaceous glands and can be very effective. Treatment must be supervised by a consultant dermatologist as serious side-effects, including possible psychiatric disturbance, can occur. The drug is also teratogenic (see TERATOGENESIS), so women who are, or who may become, pregnant must not take it. Recurrent bouts of impetigo should raise suspicion of underlying SCABIES or head lice.

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