#Recurrent vesicles which are distributed along the sensory nerve trunk

# The Lesion which is erythematous and with recurrent vesicles that are distributed along the sensory nerve trunk is?
(A). Herpes Zoster
(B). Erythema Multiforme
(C). Recurrent Aphthous
(D). Herpes Gingivostomatitis

The correct answer is A. Herpes Zoster.

VARICELLA-ZOSTER VIRUS INFECTIONS
HERPES-ZOSTER (SHINGLES)

Herpes Zoster is a recurrent regional infection caused by the Herpes Zoster virus and is characterized by vesicular eruptions over the skin and mucous membrane in a distinctively unilateral pattern.

Pathogenesis
After producing chickenpox, the V-Z virus remains dormant in the trigeminal ganglion for decades. The virus may become reactivated following stress, trauma, malnutrition and immune suppression, etc.

Clinical Features
The first branch of the trigeminal nerve is most commonly affected and the disease beside affecting the first branch, may also involve the following other branches like:
- Nasociliary nerve-Causing herpetic Keratitis
 Ciliary nerve- Causing Argyll Robertson pupil.
-Facial nerve- Causing Ramsay Hunt syndrome.

- After the prodromal phase of intense pain, the disease produces clusters of vesicles over the skin and oral mucosa; which characteristically develop on one side of the face up to the midline.

- The lesion usually develops and spreads along the distribution of the sensory nerve unilaterally on one side of the face, while the other side of the face remains completely free of symptoms.

- Within the oral cavity the vesicles also develop unilaterally over the buccal mucosa, soft palate and tongue, etc. and cause stinging pain, paresthesia and severe stomatitis.

- In due course of time the fragile vesicular lesions of the skin and the oral mucosa rupture and they leave painful, 'crateriform' ulcers. 

Histopathology
-  Herpes-zoster is histologically characterized by swelling of the infected epithelial cell cytoplasms due to intracellular edema (ballooning degeneration).

Clinical: The disease is nearly always diagnosed on the basis of its very characteristic clinical findings, e.g.
- Unilateral distribution of the lesion. 
- Early severe pain and paresthesia.
- Facial rash accompanying the stomatitis.

Serology: The disease is diagnosed by the detection of virus-specific antibodies in the serum.

Cytologic smear: Cytologic smears prepared from the vesicular fluid reveal inclusion bodies and ballooning degeneration of the infected cell.

Culture: Tissue culture using vesicular contents produces change in the culture cells which could be correlated with the clinical findings found in the primary infection.

Immunofluorescence: HZV specific antibodies are labeled with a fluorescent dye and seen microscopically.

Treatment
Aniviral drugs such as acyclovir is given along with antibiotics to prevent secondary infections.