Bacterial Skin Infections
Impetigo is a skin infection commonly caused by Staphylococcus aureus and occasionally by Staphylococcus pyogenes. It affects 1% of children.
Bullous and non-bullous are the two types of impetigo. Bullous impetigo is exclusively caused by Staphylococcus aureus with symptoms of flaccid bullae with yellow clear fluid which ruptures leading to formation of golden-yellow crust. The non-bullous appears in the extremities and face with pustules or vesicles in the reddened skin. The pustules rupture and leave a honey-colored or yellow-brown crust.
Treatment includes adequate topical application of bacitracin and mupirocin to be applied twice a day for seven to ten days. Systemic treatment is necessary for severe cases.
· Furunculosis, Folliculitis and Carbunculosis
Folliculitis is the infection of the hair follicles described as erythematous pustules and follicular based papules. Deep infections of hair follicles are called furuncles or furunculosis characterized by nodules accompanied with pustular drainage which may form to carbuncles or larger draining nodules.
Folliculitis is asymptomatic but it is painful or itchy. The posterior area of the neck, beard, axilla and scalp are the common areas affected. The furuncles usually appear in the beard as reddened, tender nodules that rupture with discharge that is purulent. Carbuncles are deep and larger nodules with purulent discharge which mostly occur in the back of the neck, thighs and back. Carbuncles are painful and tender and sometimes accompanied by malaise and fever.
The diagnosis of the three is through culture of the site.
2% erythromycin and 1% clindamycin applied topically 2 – 3 times a day in the affected areas are the treatment. It should be washed with an antibacterial soap.
Ecthyma is characterized by thick crusted ulcerations and erosions. It is usually a consequence of an impetigo that is neglected. It usually occurs in persons with no home and soldiers assigned in humid and hot climates.
The infection begins with bullae and vesicles then progresses to ulcerations with a crust which heals with scar. The legs are the common infection site.
To confirm the diagnosis, culture is done.
· Cellulitis and Erysipelas
Erysipelas is a cutaneous superficial infection involving the skin and lymphatic vessels. Cellulitis is deeper extending to the subcutaneous tissue.
Erysipelas loves elderly and young children. Some risk factors for the adult patient are venous stasis, lymphedema, diabetes mellitus, web intertrigo, alcoholism, trauma and obesity.
Erysipelas is well-defined, reddened, tender, indurated plaque on the legs or face. Cellulitis is warm, tender, red and swollen plaque with undefined borders and spreads rapidly. It is usually accompanied by regional lymphadenopathy and sometimes bacteremia.
Diagnosis is through assessment of the symptoms and culture.
The treatment of choice for Erysipelas is penicillin. For facial and more severe cases, parenteral therapy is needed. The treatment of choice of cellulitis is oral anti-staphylococcal antibiotic. Parenteral therapy is done for patients with extensive or systemic symptoms and to patients who are immuncompromised. A warm compress three to four times a day for 15-20 minutes, good hygiene and elevation of affected limb helps in healing.