1. Viral infections
Done by: Ruba Hiasat

2. Herpes Simplex Virus
Herpesvirus hominis is the cause of herpes simplex
• Route of infection: • 1-mucous membranes • 2-abraded skin
Type II virus occur mainly on the genitals, while those of type I are usually Extra genital such as oral and facial infections .. •
After the episode associated
with the primary infection, the
virus may become latent, possibly
within nerve ganglia, but still
capable of giving rise to recurrent
bouts of vesication.

3. Presentation Primary infection (acute gingivostomatitis):
• Malaise, headache, fever and enlarged cervical nodes.
• Vesicles, soon turning into ulcers, seen scattered over the: Lips and Mucous membranes.•
*The illness lasts about 2 weeks.
Herpetic whitlow
• Direct inoculation (eg. During wrestling)
• Pus-filled blisters on a fingertip.
Primary type II
• Transmitted sexually
• Multiple
• Painful
• Genital or perianal blisters which rapidly
ulcerate.

4. Recurrent (recrudescent) infections:
• Same place each time.
• Precipitated by:
• RTI (cold sores)
• Ultraviolet radiation
• Menstruation
• Stress.
• Common sites :• Face • Lips (type I) • Genitals (type II) Lesions can occur anywhere.
• Tingling, burning or pain is followed within a few hours by Erythema and clusters of tense vesicles. Crusting occurs within 24–48 h .
• The whole episode lasts about 12 days.

5. -Herpes encephalitis or meningitis .
Complications :
-Herpes encephalitis or meningitis .
- Disseminated herpes simplex: widespread –
- Eczema herpeticum
- recurrent dendritic ulcers leading to corneal scarring.
-recurrent herpes simplex infections are regularly followed by erythemamultiform
Investigations:
1-Culture
2-Antibody titres rise with primary, but not with recurrent infections.
Treatment:
• Sunblock
•Dabbing with the surgical spirit
• Aciclovir cream ( applied 5-6X a day for the first 4 days of the episode)
• More effective still is oral aciclovir 200 mg five times daily for 5 days

6. HPV Warts are caused by the human papilloma virus.
• Warts adopt a variety of patterns : -
1-Common warts: The first sign is a smooth skin- coloured papule , often more easily felt than seen. usually occur on the hands ,face and genitals . They are more often multiple than single . Pain is rare.
2-Plantar warts: These have a rough surface, which protrudes only slightly from the skin and is surrounded by a horny collar . On paring, the presence of bleeding capillary loops allows plantar warts to be distinguished from corns . Often multiple , plantar warts can be painful.
3- Mosaic warts : These rough marginated plaques are made up of many small tightly packed but distinct individual warts. They are most common on the soles but are also seen on palms and around fingernails. Usually , they are not painful.
4- Plane warts :These smooth flat-topped papules are most common on the face and brow, on the backs of the hands , and on the shaven legs of women. Usually skin-coloured or light brown, they become inflamed as a result of an immunological reaction, just before they resolve spontaneously . Lesions are multiple and painless
5- Facial warts: These are most common in the beard area of adult males and are spread by shaving. They are painless.
6 - Anogenital warts : Papillomatous cauliflower-like lesions , with a moist macerated vascular surface

7. Complications:
1-Some plantar warts are very painful.
2-Epidermodysplasia verruciformis.
3-Malignant change is otherwise rare, although infection with HPV types 16 and 18 predisposes to cervical carcinoma. HPV infections in immunocompromised patients have also been linked with skin cancer,
Treatments:
Many warts give no trouble, need no treatment and go away by themselves.
Otherwise, treatment will depend on the type of wart.
Palmoplantar warts : home treatment is best
Anogenital warts : self-treatment using podophyllotoxin
Facial common warts : These are best treated with electrocautery
Plane warts : On the face these are best left untreated and spontaneous resolution will occur.

8. VARICELLA (CHICKENPOX)
The herpes virus varicella-zoster is spread by the respiratory route; its incubation period is about 14days
Presentation : Slight malaise then papules, which turn rapidly into clear vesicles on a pink base (‘dew drops on a rose petal’).Vesicles soon become
Pustules and then umbilicate
Over the next few days the lesions crust and then clear, sometimes leaving white depressed scars. Lesions appear in crops, are often itchy and are most profuse on
the trunk and least profuse on the periphery of the limbs

9. Complications:
1-Pneumonitis, with pulmonary opacities on X-ray
2-Secondary infection of skin lesions.
3-Hemorrhagic or lethal chickenpox in patients with leukemia and other immunocompromised children and adults
Treatments:
1-Aciclovir, should be reserved for severe attacks and for immunocompromised patients.
2-Prophylactic aciclovir can also be used to prevent disease if given within a day or two of exposure.
3-Alive attenuated vaccine is now available
It is not universally effective and should not be given to patients with immunodeficiency

10. Herpes zoster (Shingles)
• Caused by the herpes virus varicellazoster/HHV-3 (reactivation) • The incidence is high, when weaken normal defence mechanisms in: • Old age • Hodgkin’s disease • AIDS • Leukemia • Shingles does not occur in epidemics • Patients with zoster can transmit the virus to others in whom it will cause chickenpox.
…Start with a burning pain, Soon followed by erythema and grouped.
• Sometimes blood-filled vesicles scattered over a dermatome.
• The clear vesicles quickly become purulent
• Over the space of a few days burst and crust.
• Scabs usually separate in 2–3 weeks, sometimes leaving depressed depigmented scars

11. Complications:
1-Secondary bacterial infection is common.
2-Motor nerve involvement is uncommon, but has led to paralysis of ocular, facial muscles, diaphragm & bladder.
3-Corneal ulcers and scarring (zoster of the ophthalmic division of the trigeminal nerve).
4-Persistent neuralgic pain, after the acute
episodeis over, is most common in the elderly
DDx:
 Pain (before the rash has appeared) 1- Acute appendicitis 2-Myocardial infarction
 An early painful red plaque may suggest cellulitis 1- Herpes simplex 2-Eczema 3-Impetigo.

12. Treatments :
Systemic treatment (within the first 5 days) Early: Famciclovir and valaciclovir Late: (supportive) # Systemic treatment is not likely # Rest # Analgesics # Calamine

13. ORF
Contagious pustules dermatitis is common in lambs. Its cause is a parapox virus that can be transmitted to those handling infected animals.
The incubation period is 5–6 days.
- Lesions, which maybe single or multiple, start as small firm papules that change into flat-topped apparently pustule nodules with a violaceous and erythematous surround - The condition clears up spontaneously in a bout a month
Complications : -
-Lymphadenitis and malaise are common.
-Erythema multiforme
-‘Giant’ lesions can appear in the immunosuppressed
Treatment : - Topical antibiotic helps to prevents secondary infection; otherwise no active therapy is needed.

14. Molluscum contagiosum
common pox virus infection which can be spread by direct contact (e.g. sexually or by sharing a towel at the swimming bath)
The incubation period ranges from 2 to 6 weeks.
• Individual lesions are shiny, white or pink, and hemispherical with a central punctum which may contain a cheesy core that gives the lesions their umbilicated look.
• Multiple lesions are common and their distribution depends on the mode of infection.
..spread by scratching and the use of topical steroids
• Untreated lesions usually clear in 6–9 months, Some leave depressed scars
Complications : - Eczematous patches , secondarily infected.
Treatments :- Many simple destructive measures cause inflammation and then resolution ..They include squeezing out the and curettage.
-doing nothing is often the best option in children

15. Thank you