BACTERIAL SKIN DISEASES

(PYODERMAS)

PYODERMAS

• A: staphylococcal skin infections

• B: streptococcal skin infections

C: other Gram-positive bacteriaD: Gram-negative bacteria

Bacterial infections

LOCALISATION

LOCAL INFECTIONS

DIFFUSE INFECTIONS

EPIDERMIS FolliculitisBulla repens

ImpetigoErythrasma

DERMIS Furuncles,CarbunclesPeriporitis

EcthymaErysipelas

SUBCUTIS HidrandenitisPanaritium

CellulitisAbscesPhlegmonaPyoderma 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

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.

• StaphStaph..aureusaureus 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

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

cellulitis

Differentiating Cellulitis and Deep Venous Thrombosis

Feature Cellulitis Deep Venous Thrombosis

Skin temperature

Hot Normal or cool

Skin color Red Normal or cyanotic

Skin surface Peau d'orange Smooth

Lymphangitis and regional lymphadeno-pathy

Frequent Nonexistent

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