An infection of the skin caused primarily by the presence of Group A Beta-hemolytic Streptococci (GABS) sometimes named Streptococcus Pyogenes. Staphylococcus Aureus can also be isolated from impetigo lesions.
Impetigo presents as a group of small blisters which rapidly coalesce and rupture. The thin yellow exudate dries forming a crust. Sites: the scalp, the legs, the arms, face and trunk. Incubation period-up to 10 days. Hair losses and scarring may occur.
Treatment: aural / topical antibiotic.
Impetigo with special reference to scalp and effect on hair.
Dr A Ahir MD LTTS Consultant Dermatologist
Definition: — Impetigo is a contagious superficial infection of the skin due to streptococci, staphylococci or both. Primary impetigo occurs as two types, impetigo contagiosum due to Group A streptococci, and bullous impetigo due to pyogenic staphylococci. Secondary impetigo implies colonization and infection of already abnormal skin by streptococci or staphylococci.
Epidemiology and bacteriology: — The relative importance of streptococci or staphylococci as the cause of impetigo varies from epidemic to epidemic and from country to country. Pure staphylococci impetigo is common in temperate climates. The streptococcal strains involved are usually of Group A. Primary impetigo is highly communicable and mainly effects pre-school children in late summer and early autumn. Staphylococci may infect the skin following initial nasal colonization whilst streptococci may directly infect the skin. Crowding poor hygiene, and neglected minor trauma may contribute to the spread in epidemics. Localized outbreaks may occur inathletes taking part in contact sports.
Pathology: — The inflammatory changes are superficial and commonly found near hair follicals. Vesiculation occurs in the epidermis at the level of the stratum granulosum. Epithelial cell debri, leukocytes and organisms are present in the vesicle. Smears for cytodiagnosis may show acantholytic cells. The skin heals without scarring.
Clinical findings: — Primary impetigo: Streptococcal impetigo begins as a transient thin-roofed vesicle with a surrounding inflammatory helo; in this type postulation and crusting occur early. Removal of established crusts leads to rapid drying of serous exudates and further crust formation. The face, particularly around the nose and mouth, is the site of predilection; lesions may be multiple and become generalized. Staphylococcal impetigo is characterized by intact blisters often without any surrounding inflammatory reaction. Impetigo neonatorum is usually staphylococcal. Secondary impetigo: Impetiginization , may occur in skin altered by minor trauma, insect bites, pediculosis capitis and eczema. Scalp infection with increasing serous matting of hair is usually associated with pediculosis capitis, atopic eczema, lichen simplex or insect bites. Regional lymphadenitis and fever may both occur.
Complications: — The most sever complication of streptococcal impetigo is acute glomerulonephritis, less commonly acute guttate psoriasis and erythema multiform may be precipitated. Toxic epidermal necrolysis may develop from staphylococcal impetigo.
Treatment: — Very mild cases may respond simply to removal of crusts and bathing with saline or hydrogen peroxide. The use of topical antibiotics for treating impetigo is limited by the tendency of many to cause allergic sensitization. Sodium fucidate is active against most staphylococci. Impetigo remits most quickly when oral antibiotics are used. A single dose of intramuscular soluble penicillin for 1 week is satisfactory for streptococcal infection, in childhood the dose will depend on the age of the patient. Most staphylococci respond to the same regime though pencillinase-producing strains may require flucloxacillin. Erythromycin is the treatment of coince for patients who are allergic to penicillin’s. in impetigo secondary to pdiculosis capitis, eczema or lichen simplex, treatment of the infection is the first priority. One bacterial inflammation has subsided, treatment appropriate to the primary disease must be started; if such treatment is inadequate, impetigo may recur. Since the normal bacterial flora may protect against virulent pathogens in diseases such as aczema, only organisms causing inflammatory signs should be treated.
9 year old, Muhammad Ali from Pelovance District Khushab.
He had impetigo since 1 month. He was treated by Local quacks.
This picture shows the involvement of scalp along with other lesions on the body, specially on the face.
Diseases of the Hair and Scalp (by Rodney Dawber, Third Edition)