Page 173 - fourth year book

SKIN DISEASES

I- Bacterial Infections
1. Impetigo contagiosa

Etiology:

Impetigo is usually caused primarily by Staphylococcus aureus, and
sometimes by Streptococcus pyogenes

Mode of transmission

 Direct contact with lesions or with nasal carriers.

N.B: Dried streptococci in the air are not infectious to intact skin. Scratching
may spread the lesions.

Predisposing factors:

Septic focus, malnutrition, poor hygiene, local pruritic disease as scabies,
Pediculosis, eczema is frequently associated with impetigo. It affects
commonly infants and children.

Incubation period: 1–3 days.

Manifestations:
1. Impetigo contagiosa has pimple-like lesions surrounded by
reddened skin.
2. Lesions fill with pus, then break down over 4–6 days and form a
thick, honey-colored crust.
3. This crust is falling off after 5-7 days leaving a normal skin or only

pigmented skin.
4. Impetigo also causes flu-like symptoms which may cause fatigue,
weakness of muscles, headaches and vomiting.

Complications:

1. Eczema
2. Cellulitis
3. Nephritis (infants)

4. Lymphangitis

Prevention
1. Good hygiene practices to prevent spreading. (with soap and
water) and bath regularly.
2. Anyone with impetigo should cover the impetigo sores with gauze
and tape.
3. The infected person's bed linens, towels, and clothing should be
separated from those of other family members.

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