Viral infections Dr. Mohammad - PowerPoint Presentation

1. Viral infections Dr. Mohammad Arif Abid

2. warts(verruca vulgaris) Description Warts are benign epidermal proliterations caused by human papilloma virus )HPV) infectiona double-stranded DNA viruswhich infects skin and mucous membranes.

3. Warts …There are over 150 different types of human papilloma virus. Transmission is by simple contact often at sites with small skin breaks, abrasions, or other trauma The virus must contact basal epithelial cells for infection to occur. Local spread is often by autoinoculation.

4. History The estimated incidence of infection is 10% in children and young adults. The peak incidence is age 12-16 years. The incubation period is variable: 1-6 months for common warts. .

5. Skin Findings common warts (verruca vulgaris)Flesh-colored papules evolve into dome shaped, gray to brown, hyperkeratotic, discreet and rough papules, often with black dots on the surface. The black dots are thrombosed capillaries. Warts are usually few in number but may be numerous Common sites are the hands, periungual skin, elbows, knees, and plantar surfaces

6. Filiform warts Are growths with finger like, flesh-colored projections on a narrow or broad base: they often occur on the face.

7. TreatmentMultiple treatments are available for warts.No single treatment is consistently highly effective. topical salicylic acid preparations(15-40%) are applied once the a dayThe preparations may be occluded with tape to increase penetration. The duration of treatment is often lengthy (8-12 weeks). Cure rate with salicylic acid preparations is 75% compared with 48% with placebo.

8. TreatmentVinegar soak Imoquimd 5% Liquid nitrogen + 17% salicylic acid Laser therapy Currete filiform wart

9. Flat Warts Description Flat warts are benign cutaneous hyperproliferation due to infection human papilloma virus. Common subtypes are types 3 and 10.

10. Flat Warts Skin Findings These pink, light brown or light yellow papules are slightly elevated and flat topped. They vary in size from 0.1- 0.3 cm. They may be few or numerous and often occur grouped or in a line as a result of spread from scratching the hands, the chin, neck, and legs. Flat warts are typically asymptomatic

11. Flat Warts Treatment If sparse numbers of lesions, a salicylic acid preparation may be applied daily directly to each lesion This treatment is limited by irritation. Applied Imiquimod 5% cream frequency affected skin at nightTretinoin cream 0.025%, 0.05%, or 0.1% 5 fluorouracil 3-5 weeks 2times/day

12. Planter Warts Description plantar warts are caused by human papilloma virus infection on the plantar foot. Warts frequently occur at points of maximal pressure, such as over the heads of the metatarsal bones, the heels or the toes. A cluster of many warts is referred to as a"mosaic wart".

13. Planter Warts Skin Findings The round, single or multiple, coalescing, flesh-colored, rough keratotic papules often look depressed. Punctate black dots within the wart, often seen on paring, are capillary loops. The papules may be tender with pressure. Some plantar warts are depressed, resembling numerous small pits.

14. Planter Warts Treatment Plantar warts do not require therapy as long as they are painless. Spontaneous resolution with time is the rule. There are multiple treatment options, Keratolytic therapy with salicylic acid Occlusal is a conservative initial treatment The wart is pared, the affected part is soaked in warm water, and the salicylicid liquid acid preparation is applied to the wart surface.

15. Planter Warts Treatment Treatment may require 6-8 weeks. Plasters with salicylic acid 40% (Mediplast) are useful in treating plantar warts. Imiquimod 5% cream may help hasten resolution; one method is to use cryotherapy first, then apply imiquimod every night under duct tape occlusion for 6-12 weeks 217

16. cryosurgery with liquid nitrogen, Vinegar soak a piece Carbon. Electrodesiccation/curettage is sometimes used,Planter Warts

17. Molluscum Contagiosum Description Molluscum contagiosum is a localized, limited viral infection of the skin, it is spread on the skin by autoinoculation and is transmitted to others by skin to skin contact The cause of infection is a DNA virus of the pox virus family.

18. Molluscum Contagiosum History Molluscum contagiosum may occur at any age, Numerous lesions and case of spread are notable in atopic patients Most lesions are asymptomatic, although tenderness and itching can occur and are usually associated with mild local inflammation lesions are transmitted by close contact.

19. Molluscum Contagiosum Skin Findings Molluscum contagiosum begins as a 1-2mm shiny, white to flesh-colored, dome-shaped firm papule. There is a small central whitish umbilication(depression) With time the papule becomes softer and more pink in color, and the central umbilication becomes more obvious.

20. Treatment…Curettage to remove the infectious central core of the lesions is fairly painless and clears the lesions. Cryosurgery with nitrogen is effective and in trained hands, rarely produces scarring. Treatment can be painful, especially for genital lesions. Imiquimod 5% Cimetidine may enhance lymphocyte proliferation and at the dose of 40mg/kg/day for two months appears to be of variable efficacy Molluscum Contagiosum

21. Herpes Simplex(Cold Sores, Fever Blisters) Description Herpes simplex virus is a double stranded DNA virus with two different virus types(types 1 and 2) Can be distinguished in the laboratory Type 1 is generally associated with vesicular ulcerative oral infections Type 2 with genital infections. Type 1 genital infections and type 2 oral infections are becoming more common, possibly as a result of increased incidence of oral-genital sexual contact

22. Herpes Simplex(Cold Sores, Fever Blisters) DescriptionHerpes simplex virus infections have two phases: Primary infection, after which the virus becomes established in a nerve ganglion Secondary phase,characterized by recurrent disease at the same site

23. Herpes Simplex(Cold Sores, Fever Blisters) Primary Infection The majority of primary infections are asymptomatic and can be detected only by an elevated immunoglobulin G antibody titer

24. Herpes Simplex(Cold Sores, Fever Blisters) Symptoms occur from 3-7 or more after contact, Tenderness, pain, mild paresthesias, or burning occurs before the onset of lesions at the site of inoculationGingivostomatitis and pharyngitis are the most frequent manifestations of the first episode of type-1 infection Localized pain, tender lymphadenopathy, headache, generalized aching, and fever are characteristic prodromal symptoms.

25. Grouped vesicles on an erythemato base appear and subsequently erode in primary herpes simple are more numerous and scattered that the recurrent infection. Lesions on the mucus membrane accumulate exudate, whereas lesions o the skin form a crust. Lesions last for 2-6 weeks and heal without scarring.

26. Herpes simplex Recurrent Infection The recurrence rate is the same as for patients who had a symptomatic or asymptomatic primary infection. Local skin trauma (eg, ultraviolet light exposure, chapping, abrasion) systemic changes(e.g menses, fatigue, fever) reactivate the virus,)Stress which then travels down the peripheral nerves to the site of initial infection and causes the characteristic focal, recurrent infection Recurrent infection is not inevitable In many individuals, there is a rise in the antibody titer, but no clinical evidence recurrence

27. Herpes simplex Recurrent Infection ….The prodromal symptoms lasting 2-24 hours, can resemble those of the primary infection, Tenderness, pain paresthesias, or burning occurs before the onset of lesion in the focal area ol the primary infection. Within 12 hours a group of lesions evolves rapidly from an erythematous base to form papules and then vesides a The dome-shaped, tense vesicles rapidly umbilicate.

28. Herpes simplex .. Treatment TreatmentTopical Agents These can be used for relief of pain When applied frequently tetracaine cream 1.8% reduces the healing time of recurrent herpes labialis lesions by about 2 days Penciclovir cream reduces a duration of herpes labialis by about half day.

29. Herpes simplex .. Treatment Oral Antiviral Agents Therapy is initiated at the first sign or symptom. Therapy is most effective when administered within 48 hours of the onset of signs and symptoms.Valacyclovir For initial episodes, 1 g is given twice a day for 7-10 days. Famciclovir For initial episode: 250mg three times a day for 7-10 days. Acyclovir For initial episodes, 400mg three times a day for 7-10 daysSuppressive therapy indicate for more than 6 episodes/ year

30. Herpes zoster(Shingles) Description Herpes zoster is a cutaneous viral infection generally involving the skin of single or adjacent dermatomes. Herpes zoster results from the reactivation of varicella virus that entered the cutaneous nerves during an earlier episode of chicken pox. Shingles is another name for herpes zoster.

31. Herpes zoster(Shingles) History This condition occurs during the lifetime of 10-20% of all people. People of all ages may be afflicted; the incidence increases with age. Patients with zoster are not more likely to have an unknown underlying malignancy. Zoster may be the earliest clinical sign of the development of the acquired immunodeficiency syndrome in high-risk individuals.

32. Herpes zoster(Shingles) Skin Findings Pre eruptive tenderness or hyperesthesia throughout the dermatome is a useful predictive sign. Pain, itching, or burning, generally localized to the dermatome, may precede the eruption by 4 or 5 days. Although generally limited to the skin of a single dermatome, the eruption may involve one or two adjacent dermatomes.

33. ofHerpes zoster(Shingles) Skin Findings…Occasionally, a few vesicles appear across the midline.Approximately 50% of patients with uncomplicated zoster have a viremia, with the appearance of 20 or 30 vesicles scattered over the skin surface outside the affected dermatome.The thoracic region is affected in two thirds of cases.

34. Herpes zoster(Shingles) The vesicles arise in clusters from the erythematous base and become cloudy with purulent fluid by the third or fourth day. The vesicles vary in size, in contrast to the cluster of uniformly sized vesicles noted in herpes simplex. Vesicles either umbilicate or rupture before forming crusts, which fall off in 2 or 3 weeksElderly or debilitated patients may have a prolonged and difficult course.

35. Herpes zoster(Shingles) Post-Herpetic Neuralgia Post-herpetic neuralgia is pain that persists more than 30 days after the rash. The incidence and duration of pain increase with age. Pain can persist in a dermatome for months or years after lesions have disappeared The pain is often severe, intractable, and exhausting. The majority of patients under 30 years age experience no pain. By age 40 risk of prolonged pain lasting longer than 1 month increases to 33%. By age 70, the risk increases to 74%.

36. Herpes zoster(Shingles) Treatment Suppression of Inflammation, Pain, and Infection Topical therapy is tried. Cool tap water can be used in a wet dressingWith oral steroids, there is a decrease of acute pain and a quicker rash resolution but no effect on post-herpetic neuralgia,

37. Herpes zoster(Shingles) TreatmentTreatment is most effective when started within the first 48 hours of infection. It is reasonable to use antiviral therapy in the patient seeking medical treatment more than 48 hours after the vesicles appear if the lesions are not completely crusted. The recommended oral dosage for adults is a 7-10-day course of :acyclovir 800 mg five times a day valacyclovir Waltrex) 1000 mg three times a day famciclovir(Famvir) 500 mg three times a day.

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