Understanding Electricity Physical Science Chapters 6,7,8,and 9.
Anatomy of Skin and Basic Skin Lesions - · PDF fileyHuman Papilloma yPoxvirus yHHV (6,7,8)...
Transcript of Anatomy of Skin and Basic Skin Lesions - · PDF fileyHuman Papilloma yPoxvirus yHHV (6,7,8)...
Viral infections
Classification of Human Viruses
DNA Viruses : Herpes Simplex Varicella Zoster Human PapillomaPoxvirus HHV (6,7,8)Epstein BarrParvovirusHepatitis B
RNA Viruses :RetrovirusTogavirusFlavivirusParamyxovirusHepatitis A,C,E Picornavirus
Aetiopathogenesis
Cell lysis (Herpes)
Cell proliferation (Pox, HPV)
Carcinogenesis (Cervical Ca, Hepatoma)
Exanthemata - Viraemia, Type 3
hypersensitivity (Arthus) reaction, virus lodged
in dermal capillaries and replicate in epidermis.
Persistent infection: Periods of latency and
reactivation (HSV, VZV)
Common Viral Infections of Skin
Human Papilloma Virus: Genital & Non-genital warts
Pox Virus : Molluscum Contagiosum
Varicella Zoster Virus: Varicella, Herpes Zoster
Herpes Simplex Virus I & I I: Herpes Simplex
Viral Exanthems
Human Papilloma Virus: Aetiopathogenesis
Human Papilloma Virus:
DNA virus, 1-80 types
Anogenital warts 6,11,16,18,31,33,51-59,70
Incubation period: few weeks to about one year.
Transmission: direct or indirect contact (nail biters, shaving, occupational, swimming pool.)
Sexual transmission: genital/ perianal wart
Autoinoculation
Clinical TypesNon genital: Verruca vulgaris (Common warts)
Verruca Plana (Plane warts)FiliformDigitate Palmoplantar Periungual
Genital: Condyloma Acuminata
Clinical featuresVerruca vulgaris: Commonest type of wartsChildren and young adults affectedAsymptomatic, hyperkeratotic papular lesions with warty excrescences Common Sites: Extremities, dorsae of hands & feetKoebner’s phenomenon present
VERRUCA VULGARIS
Clinical featuresVerruca plana: Juvenile/ flat wartsDiscrete flat skin colored or pigmented papules, coalesceKoebners phenomenonSites: face, neck, extremities
Filiform: finger like projectionDigitate: Multiple finger like projections with common base
Sites: head, face and neck
Clinical featuresPalmoplantar: Hyperkeratotic elevated or flat lesions, painful on lateral pressureMosaic and MyrmeciaDifferential diagnosis: Corn, CallosityPeriungual: Commonly associated with palmoplantar warts,Invasion of nail bed.Recalcitrant to Rx
PALMAR WART PLANTAR WART
Genital WartsCondyloma Acuminata:
Protuberant moist ,cauliflower like growths Sites: frenulum, corona and glans in men andposterior fourchette in womenAnogenital warts in children: sexual or non-sexual transmission
Bowenoid Papulosis: Multiple, grouped, warty lesions on genitals, premalignant
ComplicationsSecondary infectionPregnancy related:Proliferative growth, obstruction of labour, laryngeal papillomas in childMalignant change:Buschke-Lowenstein tumorCervical intraepithelial neoplasia (HPV 16, 18)
InvestigationsClinical diagnosisHistology: Papillomatosis, acanthosis with inclusion bodies causing vacuolation in cells
Electron microscopyDNA HybridisationImmunohistochemistry : Type of HPV
TreatmentTopical Keratolytics :Salicylic Acid, Urea, Wart solution (Lactic acid/Salicylic Acid) Chemical cautery: Podophyllin, TCACryotherapyElectrocauteryRadiosurgeryLaser therapyOthers: Imiquimod, 5FU, DNCB, Bleomycin, Interferon
TreatmentSystemic Immnomodulators: Levamisole, CimetidineInterferon Photodynamic Therapy
Molluscum Contagiosum
Pox Virus- Molluscum Contagiosum virus
MCV 1 and MCV 2
Incubation period: 2 weeks to 6 months
Transmission: contact, fomites, sexual.
Intracytoplasmic inclusion bodies
Clinical features
Dome shaped, pearly white, discrete umbilicated
papules.
Koebner’s phenomenon present
Sites: Face, neck, trunk, peri-genitals (more in
sexual transmission), eyelids.
Giant Molluscum Contagiosum / secondary
infection.
MOLLUSCUM CONTAGIOSUM
Molluscum Contagiosum in HIV
Commonly on genitals, perianal region, eyelids
Refractory Mollscum on face
Disseminated lesions
D/D: Cryptococcosis, Histoplasmosis,
Penicillinosis
Treatment
Expression / Curettage
Chemical cautery, Electrodessication,
Cryotherapy.
Topical: Imiquimod, KOH, Phenol, Cantharidine,
Cidofovir.
Systemic: Levamisole, Cimetidine
Varicella Zoster Virus
Chicken pox and shingles
Transmission: Droplet infection - nasopharynx
Varicella : primary viraemia
Zoster: Reactivation of residual latent virus in the
sensory nerve ganglion
Varicella - Clinical features
Incubation period: 2-3 weeks
Prodromal symptoms
Pleomorphic, centripetal distribution, dewdrops
on rose petal appearance
Vesicles, papulovesicles, crusting, haemorrhagic,
umbilicated lesions
Mucosal involvement
VARICELLA ZOSTER
Complications
Secondary infection
Encephalitis
Pneumonitis
Hepatitis
Varicella in HIV- Progressive, haemorrhagic,
complicated
Chronic varicella- Hyperkeratotic lesions, Acute
retinal necrosis
Treatment
Symptomatic:
Rest, Antibiotics, Anti-inflammatory, Calamine lotion
Acyclovir
Dose: 800 mg 5 times/day
Indicated in adult varicella; reduces severity,
duration & infectivity in childhood chicken pox
Prophylaxis:
Vaccine, Immunoglobulin, Acyclovir
Herpes Zoster
Clinical FeaturesReactivation of latent virus in the dorsal root ganglion of sensory nerve
Older age group
Unilateral, dermatomal, grouped vesiclesCranial (V, VII commonly), spinal (thoracic commonly)
Pre-herpetic, herpetic and post-herpetic neuralgia
HERPES ZOSTER
Herpes Zoster : Cranial nerve involvement
V Nerve:
Ophthalmic division: Herpes Zoster OphthalmicusHutchinsons sign (vesicles on nose tip)Ocular complications: uveitis, keratitis, conjunctivitis, scleritis, ocular palsy
Maxillary division: uvula / tonsils
Mandibular division : tongue / buccal mucosa
Herpes Zoster : Cranial nerve involvement
VII nerve :
Ramsay Hunt syndrome:
Earache, vesicles on pinna, facial palsy
Hearing loss, vertigo and taste sensation
impaired
Complications
Secondary infection
Post herpetic neuralgia
Scarring
Nerve Palsy
Encephalitis : in disseminated zoster
Herpes Zoster in HIV
Younger patient
Severe pre, herpetic and post-herpetic neuralgia
Multi-dermatomal, cranial nerve involvement
Haemorrhagic, disseminated
Protracted course, verrucous lesions
Acute retinal necrosis
Treatment
Symptomatic
Antivirals:
Acyclovir 800mg x 5times/day
Famciclovir 250-500 mg tds
Valaciclovir 1gm tds
Duration : 1week in immunocompetent
2weeks in immunosuppressed
Steroids : in cranial nerve involvement
Treatment of post herpetic neuralgia Steroids
Analgesics
Amitryptilline, Doxepine
Phenytoin, Carbamazapine, Sodium valproate
Gabapentine
Methylcobalamine
Topical EMLA cream
Topical capsaicin
Intralesional Steroids
Herpes Simplex Virus
HSV 1: Facial (above waist)
HSV 2: Genital (sexual)
Incubation Period : 3-7 days
Primary infection
Persist in sensory ganglion - period of latency
Recurrent infection
Clinical features
Grouped vesicles on erythematous base followed
by erosions and healing
Primary attack: severe with lymphadenopathy
and systemic complaints
Recurrences: mild with shortened clinical course
Predisposing factors: trauma, sunburn, stress,
coitus, premenstrual, high grade fever, infections,
surgery, dermabrasion
Herpes Simplex- Clinical TypesHerpes Simplex Virus I : Herpes Labialis, Herpetic Gingivostomatitis, Herpetic whitlow, Herpetic gladiatorum, Herpes sycosis, KeratoconjunctivitisHerpes Simplex Virus II: Herpes progenitalis, Herpetic vulvovaginitisComplicated: Eczema herpeticum, Disseminated HSV Herpes Simplex Virus in HIV:Chronic, recurrent, ulcer, eschar formation and dissemination
Herpes labialis
Differential diagnosisAphthosis
Erythema multiforme
Behcet’s syndrome
Pyodermas
Chancroid
ComplicationsRadiculoneuropathy
Dissemination
Meningitis / encephalitis
Erythema multiforme
Eczema herpeticum
Ocular complications
InvestigationsTzanck smear : Multinucleated giant cells
Histopathology : Ballooning degeneration,
intraepithelial blisters, inclusion bodies
HSV antibody titre : IgG/IgM
Culture
Immunofluoroscence, PCR
Electron microscopy
TreatmentSymptomatic
Topical: Acyclovir, Penciclovir, Cidofovir
Systemic:
Antiviral Primary(10 days)
Recurrence(5 days)
Suppressive6months-1yr
Acyclovir 200mg 5times/day
400mg tid 400 mg bd
Valaciclovir 1gm bd 500mg bd 500-1000 mg bd
Famciclovir 250mg tid 125mg bd 250mg bd
Viral ExanthemsMacular:
Rubella
EBV(infectious mononucleosis)
Human herpesvirus 6(roseola)
Human herpesvirus 7
Maculopapular :
TogavirusMeasles
Human parvovirus B19 (erythema infectiosum)
Viral ExanthemsMaculopapular - vesicular :
Coxsackie A (5, 9, 10,16)
Echovirus (4, 9, 11)
Maculopapular - petechial:
Togavirus (Chikungunya)
Bunyavirus haemorrhagic fever (Lassa)
Urticarial:
Coxsackie A9 and Hepatitis B
Uncommon Viral Infections of the Skin :Pox Viruses :Cowpox, Orf, Milker’s noduleEpstein Barr Virus: Infectious Mononucleousis, OHL, Gianotti Crosti, LymphomasViral insect-borne and haemorrhagic fevers:(Toga, Flavi, Arena, Filo, Bunya)Chikungunya, Dengue, Kyasanur Forest Disease, LassaPicorna Viruses :Herpangina, hand, foot and mouth disease.
Thank you