Skin Infections and Infestations
Viral Infections
- Herpesvirus
- Roseola infantum (exanthem subitum)
- Herpes simplex
- Varicella (chickenpox) and Zoster (shingles)
- Kaposi's Sarcoma (Herpesvirus - Associated) HHV-8
- Viral Infections (continued)
Herpes
Roseola
| Etiology: | Human herpesvirus 6 (HHV-6) |
| Clinical features: | Incubation 10-15 days, fever 39.5-40 °C, lasts 3-5 days As temperature falls, rash appears |
| Rash:
|
Discrete rose-pink maculopapules, neck and trunk, fades 1-2 days |
| Complications: | Febrile convulsions not uncommon |
Herpes simplex
Herpes simplex
Herpes simplex
Herpes simplex
Herpes simplex
Herpes simplex
| Etiology: | Herpesvirus hominis (HSV 1,2) |
| Clinical features: | |
| Primary Gingivostomatitis (usually HSV 1) | |
| Incubation: | 4-5 days Fever, malaise, sore throat Gums swollen, red |
| Rash: | Vesicles followed by ulcers with a yellowish pseudomembrane |
| Recovery: | Within 2 weeks. Recurrent herpes labialis occurs frequently. Herpes lesions arise in clusters in one area. |
| Herpes genitalis (HSV 1, 2) | Most often following sexual contact |
| Rash: | Vesicles followed by superficial ulceration: glans penis, vulva, vagina, or cervix |
| Recurrent infection: | More frequent with HSV 2; on average 3-4 recurrences per year. Vesicles smaller size, closely grouped on a red base, heals 7-10 days. Triggered by trauma, other infections |
| Complications: | Keratoconjunctivitis, inoculation herpes simplex (herpetic Whitlow), eczema herpeticum, systemic infection with possible encephalitis |
Varicella
Herpes zoster
| Etiology: | Varicella-zoster virus (VZV) |
Varicella |
|
Clinical features: |
Incubation 14-17 days, may have mild fever |
Rash:
|
Papules, vesicles, pustules with red areolae (crusts) Vesicles appear in crops over 2-4 days, most numerous on trunk |
Complications: |
Rare in healthy people aside from secondary infection Pneumonia especially in adults, encephalitis, Reye's syndrome |
Prevention: |
a) Zoster immune globulin (ZIG) for immunosuppressed children must be given within 3 days of exposure b) Prevention: Live attenuated vaccine for VZV, now HPB approved as of 1999 |
Zoster |
|
Clinical features: |
Pain is first manifestation, secondary to viral induced inflammation in sensory root ganglion |
Rash:
|
Onset 1.4-3.2 days later Papules, vesicles grouped, in a band along 1 or 2 dermatomes |
Recovery: |
2-4 weeks |
Complications: |
Motor involvement, ocular, post-herpetic neuralgia |
Kaposi's sarcoma
4. Kaposi's Sarcoma (Herpesvirus-Associated) HHV-8
- DNA sequences from an agent, formed in Kaposi's sarcoma lesions in HIV-positive and HIV-negative patients have homology to herpesviruses
- Because this herpesvirus-like nucleic acid is distinct from known herpesviruses, it indicates a new member of the herpesvirus family
