Skin infections/Primary pyoderma

1. Impetigo- dermis only honey crusted lesions
2. Folliculitis - hair follicle infection
3. Erysipelas - clear demarcated on face upper dermis infection
4. Cellulitis - Skin + Subcutaneos > skin is tender, warm, erythematous, and swollen, and typically does not exhibit a sharp demarcation from uninvolved skin
5. Chancriform lesions
6. Infectious Gangrene (Gangrenous Cellulitis)
7. Necrotising fascitis - Skin +subcutaneos + muscle layers

1. Impetigo

@Epidermis - superficial crusting after a infected vescicle breaks

  graph TD
    A[Non bulbous Impetigo,honey crusted leasion ];
    B[Stap.aureus];
    C[strep.pyogenes];
    D[Bullous impetigo];
    B -->D;
    C -->A;

Epidermis --> Dermis (Ecthyma)

Treatment for impetigo

• Strep
  1. Few lesions - mupirocin 2% tid or fusidic acid 2% or retapamulin 1% bid (treatment 5 days)
  2. Numerous lesion - Pen VK or Benzathine penicillin
• Staph
  1. MSSA - dicloxicillin,oxacillin
  2. MRSA - Mupirocin (7days treatment)

Ecthyma

when impetigo goes deeper into dermis mostly Strep.pyogene - punched-out ulcers covered by greenish-yel crusts that extend deeply into the dermis and are surrounded by raised violaceous margins Need enteral therapy

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2. Folliculits

Infection of a hair follicle

graph TD
    A[Staph.aureus ,Candida,P.aeruginosa];
    B[folliculitis]
    C[steroidal use ,broad spectrum antibiotics];
    A --> B;
    C --> B ;

Treatment

• Antifungal (Co-trimazole)
• Anti Bacterial (mupuriocin,Flouroquinoles)

Furuncles

Folliculitis extending deep into subcutaneous tissue

Treatment

• drainage of puss + TMP SMX + Clindamycin

Carbuncles

1. Multiple folliculitis that extend into deep connective tissue and drain at each hair follicular openings
2. fever and malaise are usually seen…

Treatment

• Drainage + Oral MSSA,MRSA,AntiFungal drugs
• Severe Infection - iv drugs Vancomycin

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3. Erysipelas

M/c Strep Group A ,70-80 % er extremities,then face

• • Fever,Elevated surface
• superficial cellulitis of the skin, with prominent lymphatic involvement
• Erysipelas is a painful lesion with a bright red, edematous, indurated (peau d’orange)

Treatment

• As its Strep A disease Penicillin or macro ideas is given

4. Cellulitis

- than Erypiseals invading connective tissue - PAthogen may vary from type of site - most commaon cause 1. Staph .aureus 2. Strep group A 3. Strep A.Galatea - extensive, with marked erythema, warmth, and swelling

5.Nectrotisong Fascitis

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6. Chancriform lesions

Chancri - ulcers in skin

graph TD
    A[Treponema pallidum,Herpes,Haemophilus ducreyi, Sporothrix, Bacillus anthracis, Francisella tularensis, Mycobacterium ulcerans, Mycobacterium marinum];
    B[ulcers in skin];
    A --> B;

A) Anthrax

graph LR
    A[Anthrax] ——-> B[at the site of infection];
    C[lethal factor gives necrosis of cells ,surrounded by edema from edema factor of anthrax toxin];
    D[chancriform lesion]
    A --> B ;
    B --> C;
    C --> D;

B) Syphilis

Primary syphilis

graph LR
    Z[localized around blood vessels]
    A[end artery damage];
    B[loss of blood to the region]
    C[formation of ulcers]
    D[systemic spread];
    Z --> A;
    A --> B;
    B --> C;
    C --> X|then| D;

Secondary syphilis

graph LR
    A[systemic spread ];
    B[papillary dermis and reticular dermis infection];
    C[edema,papillation and hyperplasia of epidermis];
    D[Condomyata lata];
    A --> B;
    B --> C;
    C --> D;

Tertiary syphilis

• Gumma formation and end-arteries damage of aorta --> Aortic Dissecton

H.Ducreyi

• ulcers are painful, well circumscribed with ragged edges, and not indurated

Francisella

graph TD
    A[ 10 to 50 bacteria by rat flea or deer tick or by inhalation];
    B[skin infection via aerosol];
    C[ Papule formation ];
    D[ulcer]
    A --> B;
    B --> C;
    C --> |into| D;

Mycobacterium

M.marinum - Contact with contaminated water from FISH TANKS. - The lesions are most often small violet papules on the hands and arms that may progress to shal, crusty ulcerations and scar formation.

Herpes

graph LR
    A[virus enter via skin or mucus membranes]
    B[virus travel to neurons of spinal cord and lives there]
    C[virus travels back via peripheral neurons and forms vesicles ]
    D[vesicles breaks to form painful ulcers]
    A -->B;
    B--> C;
    C --> D:

Infectious Gangrene (Gangrenous Cellulitis)

• rapid cellulitis + Gangrener of subcutaneous tissue

Types

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