BACTERIAL SKIN DISEASES (PYODERMAS)‏

PYODERMAS A: staphylococcal skin infections B: streptococcal skin infections C: other Gram-positive bacteria D: Gram-negative bacteria

Bacterial infections LOCALISATIONLOCAL INFECTIONS DIFFUSE INFECTIONS EPIDERMISFolliculitis Bulla repens Impetigo Erythrasma DERMISFuruncles, Carbuncles Periporitis Ecthyma Erysipelas SUBCUTISHidrandenitis Panaritium Cellulitis Absces Phlegmona Pyoderma vegetans

LOCAL INFECTIONS Ostiofolliculitis Folliculitis Furuncles Carbuncles

Folliculitis is the infection of hair follicles. is due to Staphylococcus aureus. Some of the predisposing factors include an infected wound elsewhere on the body, poor personal hygiene, diabetes mellitus, occlusive cosmetics, tight clothing or hats, exposure to chemicals and a decreased immune system.

Folliculitis The lesions may range from tiny white-topped pustules to large, yellow pus-filled lesions. may lead to furunculosis, and if left untreated, it may lead to cellulitis (a more extensive inflammation of the skin). Absces formation is the major complication of bacterial folliculitis. Therapy: topical antibiotics and/or oral antibiotics

furuncles folliculitis

Furuncle, Carbuncle A furuncle is an acute, round, firm, tender, circumscribed, perifollicular staphylococcal pyoderma that usually ends in central suppuration. A carbuncle is two or more confluent furuncles with separate heads. Some lesions disappear before rupture, but most undergo central necrosis and rupture through the skin, discharging firm, purulent, necrotic debris. Predisposed sites include the nape, axilla, and buttocks, but lesions may occur anywhere. Treatment consists of warm compresses and oral antibiotics. Surgical drainage may be required.

furuncle carbuncle

Hidradenitis suppurativa Chronic recurrent suppurative infection of blocked apocrine sweat glands occuring in the axillary, perianal and perigenital regions. Staph.aureusStaph.aureus is almost always implicated in acute cases, but gram-negative organisms (Proteus) may predominate in chronic cases. The initial lesions are tender, reddish purple nodules, appearing very much like furuncles. They subsequently become fluctuant, drain, and form irregular sinus tracts.

Hidradenitis suppurativa Vegetative granular masses develop with deep boggy nodules, and there is marked hypertrophic scarring. Treatment of acute cases consists of high-dose oral tetracycline, or erythromycin or clindamycin Surgical excision is often necessary

Risk Factors Genetics Obesity alone or with polycystic ovarian syndrome (PCOS), insulin resistance, or syndrome X Androgen dysfunction (excess male hormone) Crohn’s disease and related conditions Acne Medications (eg, lithium) Smoking (interferes with healing )

Hidradenitis suppurativa axillaris

Impetigo Staphylococcal – with pustules Streptococcal – with subcorneal vesicles or combination of the both bacteria Infants, children Face, neck or any body surface

Impetigo Rapid development of blisters filled clear yellowish fluid appearing on normal-looking skin or on top of red spots. When blisters enlarge, they become flat, sometimes with depressed centers. Next, honey-colored crust may appear in the centre.The lesions have little or no surrounding erythema. Itching and scratching leads to autoinoculation on any body surface. Most cases heal without scars

Impetigo

Ecthyma has many feartures similar to impetigo. The lesions begins as vesicles or vesiculopustules with erythematous base. The process extends more deeply penetrating through the epidermis to produce a shallow ulcer. - occurs most commonly on the legs. - heal with scarring.

Ecthyma

Erysipelas is an acute beta-hemolytic group A streptococcal infection of the skin involving the superficial dermal lymphatics that causes marked swelling. - is characterized by local redness, heat, swelling, and a highly characteristic raised, well-defined border The legs and face are the most frequently affected sites.

Erysipelas The onset can be preceded by prodromal symptoms of malaise with or without chills, fever, headache, vomiting, and joint pain. When legs are affected, edema and bullous lesions are often present.

Erysipelas Predisposing medical or postsurgical conditions, such as skin ulcers or eczematous lesions, chronic fungal infections, fissures, local trauma, venous or lymphatic compromise, and obesity are present in many patients who develop erysipelas.

Clinical types of erysipelas Erysipelas erythematosum E. vesiculosum et bullosum E. haemorrhagicum E. abscedens E. gangrenosum

Complications of erysipelas Lymphangitis and local lymphadenopathy Superficial phlebitis Cellulitis Phlegmona Later complications: Chronic secundary lymphoedema – elephanthiasis Therapy: penicilin, erythromycin,..

erysipelas

Erysipelas

Cellulitis is acute bacterial infection of the skin and subcutaneous tissue most often caused by streptococci or staphylococci Symptoms and signs: pain, rapidly spreading erythema, and edema; fever may occur, and regional lymph nodes may enlarge Risk factors include skin abnormalities (trauma, ulceration, fungal infection, other skin barrier compromise due to preexisting skin disease), which are common in patients with chronic venous insufficiency or lymphedema.

Cellulitis Cellulitis infections begin when bacteria enter cracks in the skin (through scrapes, cuts, burns, insect bites, surgical incisions, or intravenous needles).

Cellulitis The skin is hot, red, and edematous, often with surface appearance resembling the skin of an orange (peau d'orange). The borders are usually indistinct, except in erysipelas Petechiae are common Vesicles and bullae may develop and rupture, occasionally with necrosis of the involved skin. Cellulitis may mimic deep venous thrombosis

Cellulitis Fever, chills, tachycardia, headache, hypotension, and delirium may precede cutaneous findings by several hours, but many patients do not appear ill. Leukocytosis is common Cellulitis is treated with either oral or intravenous antibiotics ( penicillin, clindamycin, trimethoprim-sulfamethoxazole, cephalexin, clarithromycin and azithromycin, and vancomycin)

cellulitis

Differentiating Cellulitis and Deep Venous Thrombosis FeatureCellulitisDeep Venous Thrombosis Skin temperature HotNormal or cool Skin colorRedNormal or cyanotic Skin surfacePeau d'orangeSmooth Lymphangitis and regional lymphadeno- pathy FrequentNonexistent Cellulitis

Erythrasma is an intertriginous infection with Corynebacterium minutissimum that is most common among patients with diabetes - resembles tinea or intertrigo. common in the groin, the axillae, submammary or abdominal folds, and perineum, it presents as irregular but sharply marginated pink or brown patches with fine scaling. Wood's lamp test (when examined under this ultraviolet light, the lesions glow a coral-red color)

erythrasma

Erythrasma Therapy: erythromycin, clindamycine These measures may reduce the risk of erythrasma: Maintaining good hygiene Keeping the skin dry Wearing clean, absorbent clothing Avoiding excessive heat or moisture Maintaining healthy body weight