Herpes Simplex
Herpes simplex is one of the most common skin and mucosal infections worldwide. It is caused by two double-stranded DNA viruses of the family Herpesviridae, subfamily Alphaherpesvirinae: herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). HSV-1 typically affects the lips, face and mouth and spreads mainly through saliva or direct contact, while HSV-2 is the main cause of anogenital lesions and is sexually transmitted. With changing sexual practices, however, HSV-1 now accounts for a growing share of genital herpes.
HSV's defining biological traits are its neurotropism and its ability to establish lifelong latent infection in sensory ganglia after the first infection. The virus lies dormant in the nuclei of ganglion cells without actively replicating, which lets it evade the host's immune system and current antiviral drugs. When triggered by fever, emotional stress, tissue injury, ultraviolet (UV) light from the sun or weakened immunity, the virus reactivates and travels back down the sensory nerve to the original area of skin or mucosa, causing a recurrent outbreak.
At Haute-Derma, managing HSV goes beyond cutting short an acute blister outbreak. We also aim to optimize long-term suppressive therapy, reduce recurrences and prevent dark marks, pitted scars and secondary infection. Using accurate diagnosis with dermoscopy, Tzanck smears and real-time PCR typing, our doctors build an individualized plan that combines systemic antivirals with targeted skin barrier repair.
Pathogenesis and Latency in Nerve Ganglia
Entry Receptors and Cell Recognition
- Cell entry: Viral envelope glycoproteins (gB, gC, gD, gH/gL) bind host cell surface receptors, including heparan sulfate, HVEM (herpesvirus entry mediator) and nectin-1.
- Primary replication: The virus enters skin or mucosal epithelial cells and replicates explosively, causing direct cytolysis and producing shallow intraepidermal blisters surrounded by inflammation.
Establishing Latency and Reactivation
- Retrograde transport: Virus particles travel from sensory nerve endings along the axon to the ganglion cell body—the trigeminal ganglion for facial HSV-1 and the sacral dorsal root ganglia for genital HSV-2.
- Latency: Viral DNA persists as a circular episome in the neuron's nucleus. Only short RNAs called latency-associated transcripts (LATs) are produced, maintaining dormancy and blocking apoptosis.
- Anterograde transport: When triggered (UV light, hormonal changes, surgery, stress), the virus replicates again and travels back to the skin or mucosa supplied by that nerve, causing a recurrence in the same spot.
Clinical Features
Orofacial Herpes (HSV-1):
- Prodrome: Tingling, itching, burning or a hot sensation on or around the lips 6–24 hours before lesions appear.
- Skin lesions: Clusters of blisters on a red base. They quickly turn cloudy and rupture, leaving shallow scalloped erosions that crust over with honey-yellow crusts.
- Healing time: Heals on its own within 7–10 days without scarring, provided there is no secondary infection.
Genital Herpes (HSV-2 / HSV-1):
- Primary episode: Often severe, with clusters of shallow blisters on the glans, penile shaft, vulva, vagina or around the anus. The blisters break into very painful shallow ulcers, accompanied by fever, headache, muscle aches and tender swollen lymph nodes in both groins.
- Recurrent episode: Much milder, with fewer lesions and less pain, healing within 5–7 days.
Special Forms Seen in Dermatology:
- Herpetic whitlow: Deep, very painful blisters on a fingertip after the virus enters through a scratch (common in dentists, health workers and children who suck their fingers).
- Herpes gladiatorum: Widespread HSV infection on the neck, face and forearms spread by skin-to-skin contact in contact-sport athletes (wrestling, judo).
Differential Diagnosis of Blistering and Ulcerative Mucocutaneous Conditions
| Herpes Simplex (HSV) | Shingles (Varicella Zoster) | Aphthous Ulcers (Aphthous Stomatitis) |
|---|---|---|
| Around the lips and nose, genitals, anus | One side of the body, following a dermatome | Inner cheeks, lips, tongue (not on the skin) |
| Clusters of small blisters on a red base | Blisters or pustules in a one-sided band | Round or oval ulcers with a yellow-gray base and red rim |
| Tingling, mild burning pain | Severe stabbing or burning pain | Marked pain when eating or talking |
| Tzanck smear (+), HSV PCR (+) | Tzanck smear (+), VZV PCR (+) | Tests negative; clinical diagnosis |
How We Diagnose Herpes Simplex at Haute-Derma
Clinical Examination and Dermoscopy:
- Well-defined clusters of blisters on a red base.
- Dermoscopy: Dome-shaped blisters with clear or slightly cloudy fluid, ringed by dotted vessels at their base.
Tzanck Smear: Fluid and a gentle scraping from the base of a freshly opened blister are stained with Giemsa or Wright stain. Multinucleated giant cells and ballooning degeneration of epidermal cells are seen.
Molecular Testing (Real-Time PCR): The most sensitive and specific method. It detects viral DNA and distinguishes HSV-1 from HSV-2, which is especially important for predicting how often genital herpes will recur.
Management and Treatment at Haute-Derma
Systemic Antiviral Regimens
- Acute episodes (primary infection or severe recurrence):
- Valacyclovir: 1,000 mg orally twice daily for 7–10 days (primary infection) or 500 mg twice daily for 3–5 days (recurrence). Valacyclovir is our preferred choice at Haute-Derma because its oral bioavailability is much higher than acyclovir's.
- Acyclovir: 400 mg orally three times daily for 7–10 days.
- Famciclovir: 250 mg orally three times daily for 7–10 days.
- Long-term suppressive therapy:
- Indications: More than 6 recurrences a year, or outbreaks that seriously affect emotional well-being and quality of life.
- Regimen: Valacyclovir 500 mg orally once daily, continuously for 6–12 months, followed by a review of recurrence frequency.
Local Care and Skin Barrier Repair
- Antisepsis and pain relief:
- Apply a gentle, alcohol-free antiseptic such as octenidine dihydrochloride or nano-silver to the blisters twice daily to prevent staphylococcal superinfection.
- Avoid corticosteroid ointments on active blisters, as they can make the infection spread.
- Recovery and preventing dark marks:
- Once lesions have crusted over, use a moisturizer with ceramides, zinc oxide, panthenol (B5) and niacinamide to speed epidermal repair.
- Apply broad-spectrum sunscreen to the affected area to prevent post-inflammatory hyperpigmentation and reduce the chance of UV triggering a new outbreak.
