1. CHAPTER 4 MICROBIAL DISEASES OF THE SKIN Miss Rashidah Hj Iberahim

2. Content  Bacterial skin diseases*  Viral skin diseases  Fungal skin diseases  Wound infection – gas-gangrene*

3. Bacterial infections

4. Gram positive infections  Folliculitis and other skin lesions  Scalded skin syndrome  Scarlet Fever  Erysipelas Staphylococcus spStreptococcus sp

5. Folliculitis(pimples / pustules) S. aureus colonize skin and upper resp. tract of infants within 24 hrs after birth Invade thru hair follicle- producing folliculitis (form of pimples and pustules) Encapsulated of abcess- x shedding n antibiotic reach the area Treatment-surgery  Spread thru hosp personnel, asympt carrier n hosp visitors/catheters and splinters for older patient /nasal droplets and fomites  100 m/org were enough to cause infection in suture Pathogenesis Transmission

6. on base of eye lashes – sty

7. A larger and deeper form – abscess

8. Exterior abscess – furuncle / boil

9. Massive lesion - curbuncle

10. Scalded Skin Syndrome  By certain exotoxin-producing strain of S.aureus (2 types exfoliatins)  Common in infant; adult (toxic shock syndrome)  Exotoxin move thru veins to the skin causing outer layer peeling off in leaflike sheets  Can lead to septicemia and very antigenic  Can cause reinfection – antibiotic very important 1. 1 st stage – redness of surrounding area 2. 2 nd stage – 1-2 days large, soft and easily ruptured vesicles around the body 3. 3 rd stage – the lesion getting dry and scale PathogenesisSymptoms

11. Peeling off skin

12. Scarlet Fever Pathogenesis  Also known as scarlatina  By Streptococcus pyogenes  Contain 3 types of erythrogenic toxin – reddening  The strain was 1 st infected by temperate phage – erythrogenic toxin that leads to rash  Only infecting new exposure pt  low- virulent strain – glomerulonephritis / rheumatic fever  Reinfection that already defends by previous antibiotic – leads to strep throat (but carrier of scarlet fever)  Might also caused by fomites

13. Rash  The best medicine is Penicillin – decrease mortality rate

14. Erysipelas  Face- small, bright, raised, rubbery lesion.  Beta hemolytic gp A Strept.  Always occur after pt having surgery or wounds  Producing hyaluronidase enzyme and toxin  Minor abrasion—  sup. Lymph vessels (causing septicemia, abscess,pneumonia, endocarditis, arthritis, death) Pathogenesis

15. Viral Diseases

16. Rubella  Rashes appear on trunk after 16-21 days after infection  Caused by togavirus  2ndary: arthritis and arthralgia  Can caused congenital rubella syndrome  Mainly through nasal secresion  Direct contact among children age 5 – 14  Infected infants expose to hospital personnel The diseaseTransmission

17. Rubella  Immunity assessment on pregnant woman  Rubella – specific IgM antibody  Other variety serology test  Currently using rubella vaccine (MMR) DiagnosisPrevention

18. Measles/ Rubeola  Caused by Rubeola virus  Koplik’s spots – bluish specks in upper lips and cheek mucosa  Rubella – pink n flat rash  Rubeola – red and raised  Other complications :  Measles encephalitis  Subacute sclerosing panencephalitis (SSPE)  Diagnose by its symptoms  2 nd accompanied by bacterial infection  Using the same vaccine as rubella and mumps (MMR) Diagnosis and prevention

19. Chicken pox and Shingles  1 virus – 2 diseases  CP – varicella, S – zoster (varicella-zoster virus)  2 nd inf by S. aureus  In children  Damages in blood and lymphatic drainage  During latent period, stay in ganglia of nerve cells  CP = Causing blood clot and hemorrhage, Cause death  S = pain, burning, prickling of the skin when it reactivate The diseaseSymptoms

20. Disease progression 1. Virus enter upper respiratory tract/ conjuctiva – replicates 2. Carried by blood to various tissues – replicates 3. Release of viruses causes fever and malaise 4. After 14 – 16 days, present of small, irregular, rose-coloured skin lesions 5. Fluid become cloudy, dry and crust over 2-4 days (virus cycle) 6. Rashes start from scalp and trunk, face and limbs, to mouth/throat/ vagina, and may spread to resp tract and GIT

21. Chicken pox and shingles  CP – Infect between 5- 9 yrs old  V – age >45 yrs old  Spread by respiratory secretion and fluid from moist lesion (not the dry lesion)  Using rapid laboratory test  Treatment – antiviral agent (valtrex and neurontin) TransmissionDiagnosis and treatment

22. Gas gangrene Wound infection

23. Gas Gangrene  Caused by more than 1 bacteria = Clostridium sp.  Spores of the bacteria expose during injuries and surgery  The symptoms getting severe because of toxin and enzyme production  Suddent onset = 12-48 hrs after exposure  Foul odour  Ferment muscle carbohydrates  “snap, crackle and pop”  High fever, shock, massive tissue destruction, blackening of tissues PathogenesisSymptoms

24. Photograph before right leg amputation (hemipelvectomy) of a patient with gas gangrene. The right thigh is swollen, edematous and discoloured with necrotic bullae(large blisters). An impressive crepitation is already palpable. At this juncture, the patient is in shock.hemipelvectomynecroticbullaecrepitationshock

25. Others diseases

26. 1. Wart Caused by Human Pappiloma Virus (DNA)

27. Plane wart Plantar wart Face, back of hands sole

28. Genital wart  Condylomata accuminata  Penile, vulvar skin, perianal area  Sexual partner  Child---sexual abuse  Some: oncogenic:16, 18

29. 2. Molluscum contagiosum  Pox virus  Child  Face, neck  Central punctum  Hunderson-patterson bodies

30. Superficial mycosis Deep mycosis Fungal

32. Dermatophyte infection  Skin  Hair  Nails

33. Tinea pedis Adult (athlete’s) Toe webs, instep T.rubrum, T.mentagrophytes

35. Tinea ungum T.rubrum, T.mentagrophytes

36. Tinea corporis: Trunk Active edge T.rubrum

37. T.cruris

38. T.manun

39. Tinea capitis Well circumscriped pruritic scaling area of hair loss  Black dot (T.tonsurans)  Gray patch (M.audouinii),  Kerion (T.verrucosum)  Favus (T.schoenleinii)