1. Bacterial and Viral Disease of the Skin

2. Bacterial infection of the skin
The surface of the skin has microrganisms, which are most numerous in moist hairy areas rich in sebaceous glands.
Staphylococcus aureus and group A beta-hemolytic streptococci account for the majority of skin and soft tissue infections.

3. S. aureus invades skin and causes:
Impetigo, folliculitis, cellulitis, and furuncles.
Elaborationإعداد of toxins by S. aureus causes the lesions of bullous impetigo and staphylococcal scalded skin syndrome.
Streptococci invade traumatic skin lesions and cause impetigo, erysipelas, cellulitis, and lymphangitis.

4. Impetigo Caused by staphylococci streptococci or by both together.
the bullous type is usually caused by Staphylococcus aureus because exfoliativeتقشر toxins produced by S. aureus cleave the cell adhesion molecule
the crusted ulcerated type is caused by streptococci.

5. Presentation
A thin-walled clear blister forms before rupturing to leave area of exudation and yellowish crusting
lesions enlarge and become contiguous with the others
often multiple particularly around the face.

6. Crusted lesion

7. Investigation and treatment impetigo
The diagnosis is usually made on clinical grounds.
Gram stains or swabs taken for culture
Mild infection and localised lesions
Topical antibiotics
Widespread lesions or more severe infection
Oral Flucloxacillin

8. Ecthyma
This term describes ulcers forming under a crusted surface infection.
may be due to insect bite or of neglected minor trauma .
Due to Staph aureus or Strep
Usually on the lower extremities of children Buttocks thighs and legs
the ulcer is full thickness and heals with scarring and pigmentation.

9. Ecthyma Ulcer and scars

10. Folliculitis Folliculitis is inflammation of the hair follicle
painless or tender pustule that eventually heals without scarring.
usually with Staphylococcus aureus
Frequently seen in beard area, axillae or buttocks
Legs—Chronic folliculitis

11. Pustules are localized to the hair follicles (folliculitis)

12. Treatment of ecthyma
Superficial lesions – may respond to local antiseptics or persistent cases may need topical antibiotics
Widespread and severe folliculitis – oral flucloxacillin

13. Superficial folliculitis
Deep folliculitis (next)
Furuncle and carbuncle
Sycosis barbae تينة اللحية

14. Furuncle (Boil)
Deep inflammatory nodule developing from a preceding folliculitis
Usually with Staphylococcus aureus.
Begins as a firm, tender, erythematous nodule that becomes fluctuantمتموجة and painful and commonly ruptures spontaneoiusly and later may discharge pus
May have Fever
healing leave a scar

15. Lesions favor areas prone to friction or minor trauma thighs, buttocks, groin and axillae.
Complication
Cavernous sinus thrombosis is an unusual complication of boils on the central face.
Septicaemia may occur but is rare.

16. Treatment -drainage of pus and Systemic treatment with flucloxacillin
furuncle purulent material from a single opening.

17. Carbuncleجمرة
A group of adjacent hair follicles becomes deeply infected with Staphylococcus aureus, leading to a swollen painful suppurating area discharging pus from several points.
larger than a Furuncle (Boil)
The pain and systemic symptoms are greater than those of a boil.
Diabetes should be excluded.

18. Carbuncle

19. Treatment Incision and drainage .
Needs both topical and systemic antibiotics.

20. Sycosis barbae S. aureus in men and increase with shaving
follicular papules or pustules
TREATMENT: Localized inflammation is treated topically Extensive disease is treated with oral antibiotics

21. Cellulitis
The subcutaneous tissues are involved and the area is more raised and swollen, and the erythema less marginated.
malaise, chills, and fever
Cellulitis often follows an injury and favours areas of oedema.
group A streptococci are the responsible organisms.
Erysipelas is a superficial cellulitis

22. Cellulitis. There is erythema, edema, and tenderness.

23. Treatment of cellulitis
Elevation and rest
systemic antibiotics oral or I.V
Recurrence after antibiotic treatment occurs in 18% to 30% of cases.

24. PARONYCHIAداحسية
bright red swelling of the proximal and lateral nailfold
Painful
rapid onset
Treatment
warm water compresses may be effective.
topical or systemic antistaphylococcal antibiotic

25. STAPHYLOCOCCAL SCALDED SKIN SYNDROME (Ritter’s disease)
Erythema and tenderness followed by the loosening of large areas of overlying epidermis
More In children and infant
Caused by a toxin produced by staphylococcal infection elsewhere(e.g. impetigo or conjunctivitis).

26. Normal Skin
Blister

27. toxins cleave the superficial skin adhesion molecule to disrupt خلل adhesion high in the epidermis causing the stratum corneum to slough offتنصل .

28. STAPHYLOCOCCAL SCALDED SKIN SYNDROME (Ritter’s disease) treatment
Tender red skin
Heals day
Fluid from bullae is sterile but the S. aureus can be isolated from distant sites, such as the nose.
TREATMENT
oral or intravenous flucloxacillin
The patient’s skin lubricated with light lotions

29. Viral diseases of the Skin
Warts
Smallpox
Chickenpox -Shingles
Herpes Simples
Measles
Rubella

30. WART
Warts are epidermal neoplasms that are caused by human papillomaviruses (HPVs)
DNA viruse
Common in children and young adults
Direct contact

31. wart

32. warts in the beard area. Shaving spreads the virus over wide areas of the beard.

33. GENITAL WART STD Oncogenic HPVs ( Cervical cancer)
Usually more persistent and difficult to treat .

34. wart treated with cryotherapy
TREATMENT of warts
Cryotherapy ( Liquid nitrogen)
Keratolytic (salicylic acid )
laser
Immunotherapy
wart treated with cryotherapy

35. Smallpox
DNA virus
highly contagious through inhalation of airborn variola virus
Fever malaise, headache
progressing to vesicles and pustules

36. Chickenpox and smallpox can be distinguished by:
chickenpox does not usually affect the palms and soles.
chickenpox pustules are of varying size due to variations in the timing of eruption
Smallpox pustules are all very nearly the same size

37. Treatment of smallpox Supportive Systemic antiviral
After vaccination the WHO certified the eradication of smallpox in 1979.

38. VARICELLAE ZOSTER VIRUS (VZV)
CHICKENPOX
HERPES ZOSTER

39. Chickenpox herpes virus varicella-zoster Incubation period : 2 weeks
Prodromمبادر of respiratory symptoms followed by disseminated red macules with central vesicles.
often itchy
Over the next few days the lesions crust and then clear

40. Symptoms are more severe in adults. Complications
Pneumonitis
Secondary infection of skin lesions.
Scarring.

41. Treatment of Chickenpox
Acyclovir antiviral
A live attenuated vaccine is now available
The patient is contagious 5 days before and 5 days after skin eruption

42. HERPES ZOSTER
Zoster results from reactivation of varicella virus that entered the cutaneous nerves during an earlier episode of chickenpox

43. HERPES ZOSTER
patient develop grouped vesicles on erythematous base which ulcerate
vesicles scattered over a dermatome
Post-herpetic neuralgia (PHN) which usually persist for around 4 weeks.

44. Herpes zoster (ophthalmic zoster) can lead to corneal ulcers and scarring.

45. Systemic treatment should be given to all patientsif diagnosed in the early stages of the disease.
acyclovir
It is essential that this treatment should start within the first 5 days of an attack
post-herpetic neuralgia treatment

46. Herpes Simplex Human Herpes virus I and II
type I are usually extragenital
The lesions caused by type II virus occur mainly on the genitals
Direct contact
After the the primary infection, the virus become latent within nerve ganglias capable of giving rise to recurrent

47. burning sensation the patient develop grouped vesicles on erythematous base

48. Herpetic whitlow Recurrence at the same location was the clue to the diagnosis.

49. Diagnosis Treatment Tzank smear Direct fluorescent antibody test
Viral culture
Blood serology
Treatment
Acyclovir

50. Measles highly contagious viral disease
The virus is spread by coughing and sneezing close personal contact
Most cases have a benign course.
serious complications include blindness, encephalitis
People who recover from measles are immune for life.

51. Koplik’s spots (blue-white spots with a red halo) appear on the buccal mucous membrane 24 to 48 hours before the exanthemطفح and remain for 2 to 4 days

52. The rash begins on the fourth or fifth day on the face and behind the ears, but in 24 to 36 hours it spreads to the trunk and extremities

53. MANAGEMENT OF MEASLES
Nutritional support and prevention of dehydration with oral rehydration are necessary.
Antibiotics treat eye and ear infections and pneumonia.
Live vaccine if given within 72 hours of measles exposure may provide protection

54. Rubellaالألمانية German measles
Lymphadenopathymay appear 4 to 7 days before the rash
The eruption begins on the neck or face and spreads in hours to the trunk and extremities The lesions are pinpoint to 1 cm oval rosy red macules or maculopapules.

55. Rubella

56. CONGENITAL RUBELLA SYNDROME
Pregnant women who have rubella early in the first trimester may transmit the disease to the fetus, which may consequently develop a number of congenital defects (hearing loss or eye cataract)
Prevention is by immunization with the combined measles-mumps-rubella (MMR) vaccine.

57. Syphilis Infection with Spirochete ملتوية called Treponema pallidum
The most important route is through sexual contact with an infected partner
Incidence is currently rising sharply with concurrent HIV infection.

58. القرحة

59. 1ry syphilis ( 1ry chancre)
Painless well-demarcated indurated صلب genital ulcer with lymphadenopathy.
Serology is negative
Smear for :
Dark filed examination
Direct fluorescent antibody test

61. 2ry syphilis Asymptomatic generalized monomorphic eruption with lymphadenpathy with characteristic involvement of the palms/soles and mucous membrane. Serology is positive ( VDRL / RPR Rapid Plasma Reagin) Skin biopsy

63. 3ry syphilis Cuatneous Well-demarcated nodules with or without ulceration mainly over the trunk “GUMMAصمغية ” . Severe mutilationتشويه can happen when it involve the face Diagnosis can be made through skin biopsy

64. GUMMA

65. Treatment of syphilis Penicillin
Doxycycline or azithromycin are alternatives for those with penicillin allergy.

66. MYCOBACTERIAL I.TUBERCULOSIS Exogenous tuberculosis chancre
Direct extension
scrofulodermaخنازير جلدية
Hematogenous spread
lupus vulgaris

67. Scrofuloderma
The skin overlying a tuberculous lymph node or joint may become involved . The subsequent lesions later form scars, fistulae and abscesses
most commonly seen in the neck.

69. Lupus vulgaris Most common type of Cutaneous TB Head and neck
Red-brown nodules and plaques
(apple-jelly nodules) when it ulcerate it heal with unhealthy scar

71. II. LEPROSY
M.leprae
Faceoral transmition
Close contact in endemic area (India)
Delay in presentation ( 20 years)

72. Classification of leprosy
Indeterminate stage
ill-defined hypopigmented anesthatic hairless dry patch
Tubercaloid leprosy
Few ( < 3) well demarcated scaly red anesthatic hairless dry annular plaques with central clearing
Adjacent nerve swelling

73. tuberculoid type

74. Lepromatous leprosy
Multiple diffuse symmetrical skin-colored to red-brown plaques and nodules
Leonineأسدي face
blindness
Peripheral neuropathy

75. lepromatous type

76. Treatment of leprosy Dapsone
Combination (multi-drug therapy-MDT), usually with rifampicin, and also with clofazimine for lepromatous leprosy.