CHAPTER 14
VIRAL INFECTION OF THE SKIN
I. Herpes viruses
Table: Types of the Human Herpes virus
|
Type |
Associated disease |
|
HHV-1, HSV-1 |
Herpes simplex infedtion type 1 gingivostomatitis (P) herpes labialis (P/R) herpes simplex of trunk & upper extremitise (P/R) herpes gladiatorum (P) eczema herpeticum (Kaposi's varicelliform eruption) (P/R) herpes genitalis (P) (erythema multiforme) (R) neonatal herpes simplex infection (P) |
|
HHV-2, HSV-2 |
Herpes simplex infection, type 2 herpes genitalis (P/R) herpes simplex of buttock & lower extremities (P/R) herpetic whitlow (P/R) (erythema multiforme) (R) neonatal herpes simplex infection (P) |
|
HHV-3, VZV |
Varicella, Herpes zoster |
|
HHV-4, EBV |
Infectious mononucleosis (Epstein-Barr virus disease) |
|
HHV-5, HCMV |
Human cytomegalovirus disease |
|
HHV-6 |
Exanthema subitum |
|
HHV-7 |
Exanthema subitum |
|
HHV-8 |
AIDS-related Kaposi's sarcoma |
A. Herpes simplex virus infection, types 1 and 2iPซแv]j
1. Non genital herpes simplex virus infection
a. Age: most commonly young adults: range, infancy to senescence
b. Etiology: HSV, a DNA virus, types 1 & 2; type 1 far more common than type 2
c. Transmission: skin or mucosa /skin or mucosa
d. Incubation period: 2- to 10- days for primary infection
e. Precipitating factors for recurrence: UV irradiation, menstruation, pregnancy, "cold".
f. Diagnosis
1) Tzanck smear (giant cells, viral antigen)icANฑj
2) serum titer (CF, NT, EIA)
3) Direct virus detection: virus culture, immunofluorescence, DNA diagnosis (PCR), EM
Primary herpes:
a. Skin symptoms: tingling, burning and itching.
b. Skin Lesions: Type; pinhead size vesicles on an erythematous base then erosions, crusts.
c. Arrangement: herpetiform.
d. Site of prediction: mouth, whole body (Kaposi's varicelliform eruption) and fingers (herpetic whitlow).
e. Other signs and symptoms: fever, headache, regional lymphadenopathy.
f. Treatment: AcycloviriAVNrj(Zovirax), 200 mg PO 5 times a day for 5 days. NSAID.
Recurrent herpes:
a. Skin symptoms: tingling, burning and itching, even if any, milder than primary herpes.
b. Skin symptoms: red edematous papuleจsmall group of vesicles.
c. Arrangement: herpetiform, linear, zosteriform.
d. Site of prediction: face, lips or anywhere. only rarely on the mucous membrane.
e. Treatment: Acyclovir (Zovirax), 200 mg PO 5 times a day for 5 days. NSAID. For mild cases, acyclovir ointment 3 times a day for 5days.
2. Genital herpes simplex virus infection
a. Transmission: skin or mucosa /skin or mucosa
b. Incubation period: 2- to 10- days for primary infection
c. Precipitating factors for recurrence: menstruation, pregnancy, "cold", physical and mental stress...etc.
d. Diagnosis: (จNon genital infection).
e. Treatment: (จNon genital infection).
Primary herpes:
a. Etiology: HSV types 1 & 2; type1 = type 2.
b. Age: sexually active young adults.
c. Skin symptoms: initial burning, red edematous papules, then vesicles.
d. Skin lesions: vesiclesจerosionsจulcers.
Recurrent herpes:
a. Etiology: HSV type 2, less severe than primary, but more distressing.
b. Skin lesions: vesicles on the erythematous baseจerosions.
B. Herpes zosteriั๓แv]j
a. Etiology: The varicella-zoster virus (VZV) remains in the dorsal root ganglia after the varicella infection and surfaces later in life to cause herpes zoster infection.
b. Transmission: recrudescence
c. Skin syndromes & lesions:
1) pain, tenderness & paresthesiaจpapules จvesicles-bullaeจpustulesจcrusts.
2) pain usually persists throughout the eruptin but lessens with time.
d. Arrangement: zosteriform (dermatomal) with herpetiform clusters of lesions. unilateral.
e. Diagnosis: (จHSV infections).
f. Course & prognosis: Postherpetic neuralgia (PHN)iั๓แv]ใ_oษj.
g. Motor paralysis is reported in up to 5% of patients.
h. Treatment: Acyclovir (Zovirax), 800mg PO 5 times a day, or 250 mg d.i.v. 3 times a day for 7 days. NSAID, VB12, predonisolone, pain block.
II. Poxviruses
Molluscum contagiosumi`๕ซ๎ฎ๎j
a. Etiology: Molluscum contagiosum virus is a large DNA virus.
b. Transmission is by personal contact.
c. Age: children and their parents (may be epidemic).
d. Risk factors: HIV-infected individuals may have hundreds of mollusca.
e. Skin lesions: pearly white or skin colored papules ~nodules with central umbilication.
f. Diagnosis: A core could be expressed from the lesions. Identification of molluscum bodies.
g. Treatment: resection, application of liquid nitrogen.
application of AgNO3 by ointment or paste. Wait & See.
III. Papova viruses
Papova = papilloma + polyoma + vacuolating agent.
These virus are characterized by tumorigenesis.
Only papillomaviruses are important in dermatology.
A. Papilloma viruses
Etiology: human papillomavirus (HPV), a DNA virus. There are more than 70 genotypes.
Table: Types of the human papilloma virus
|
BENIGN |
6, 11+ |
Condyloma acuminatum |
|
|
1 |
Myrmecia |
|
|
2+ |
Verruca vulgaris |
|
|
3+ |
Verrucae; lanae juveniles |
|
|
9+ |
Epidermodysplasia verruciformis |
|
|
60 |
Plantar epideremal cyst |
|
MALIGNANT |
16, 18+ |
Bowenoid papulosis, genital Bowen's disease, cervical cancer |
|
|
5+ |
Epidermodysplasia verruciformis |
+: other types are also reported.
Table: Treatment of HPV infection
|
DISEASE |
Liquid N2 |
EK |
Surgery |
Topical bleomycin |
Yokuinin |
Others |
|
Condyloma acuminatum |
|
|
~ |
|
~ |
topical podophyllin |
|
Myrmecia |
|
~ |
~ |
~ |
|
topical GA |
|
Verruca vulgaris |
|
|
~ |
|
|
topical GA |
|
Verruca plana juveniles |
|
~ |
~ |
~ |
|
|
|
Plantar Epidermal cyst |
~ |
~ |
|
~ |
~ |
|
|
Bowenoid papulosis/ Genital Bowen's disease |
/ |
/ ~ |
/ |
|
~ |
|
IV. Parvo viruses
Erythema infectiosumi`๕ซgมj
-Caused by human parvovirus B19. It may also causes transient aplastic crisis (TAC) and hydrops fetalis.
V. Hepadna viruses
Gianotti diseaseiMAmbeBaj
-Caused by hepatitis B virus. The virus may be related to lichen planus.
VI. Picornaviruses
Hand, foot and mouth diseasei่ซ๛aj
-Caused by Coxsackie virus A16 (sometimes A4,5,7,10, B2 and 5) with occasional outbreak due to enterovirus 71.
VII. Paramixoviruses
Measlesi]jis caused by measles virus.
VIII. Toga viruses
Rubella (]), or German measles
-Caused by rubella virus. The virus also causes congenital rubella syndrome (CRS).
IX. Retro viruses
A. Adult T cell Lymphoma/Leukemia (ATL/L)iฌlTืEa^p๎j
-Caused by human T lymphotropic virus (HTLV-I).
-The virus causes
a. Specific eruptions: reddish papules~nodules, erythematous patches. with / without induration, tumor formation, erythroderma, purpuric change, mycosis fungoides like lesions...etc.
b. Non-specific eruptions: eczematous lesions, xeroderma, secondary ichtyosis, keratoderma on the palms & soles...etc.
B. Acquired Immune Deficiency Syndrome (AIDS)iใVซฦusSว๓Qj
1. Caused by human immunodeficiency virus, type I (HIV-I).
The specific eruption of HIV infection is acute HIV exanthema, which shows truncal maculopapular eruption or mononucleosis-like eruptions with fever, myalgias and wheal followed by lymphadenopathy.
2. Common cutaneous manifestation of AIDS
a. Viral: acute HIV exanthema, herpes simplex, herpes zoster, AIDS related Kaposi's sarcoma, molluscum contagiosum, warts/condyloma, hairy leukoplakia.
b. Fungal: Candida albicans infections, tinea versicolor, seborrheic dermatitis (may be caused by pityrosporum ovale), dermatophytes.
c. Bacterial: Staphylococcus aureus infections.
d. Proliferative disorders: xeroderma, pruritic papular eruption.
e. Miscellaneous: cutaneous drug reactions, yellow nails (caused by Pneumocystis carinii pneumonia), premature graying of hair.
Table: Number of CD4+ T lymphocytes and opportunistic infection.
|
# of CD4 + T lymphocytes / mm3 |
Disease |
|
500-700 |
herpes zoster |
|
200-500 |
TB, Kaposi's sarcoma, oral hairy leukoplakia (by EBV) |
|
100-200 |
Carinii pneumonia, systemic candidiasis |
|
50-100 |
toxoplasma encephalitis, systemic cytomegalovirus infection, systemic atypical mycobacterium infection |
|
< 50 |
malignant lymphoma, HIV encephalitis |