Skin Diseases

Question 1

Shingles or Herpes zoster
Definition 
Causes
Signs and symptoms 
Investigations 
Complications 
Differential diagnosis 
Management

Answer 1

Definition
Shingles is A reactivation of the chickenpox virus in the body, causing a painful rash.
Anyone who’s had chickenpox may develop shingles. It isn’t known what reactivates the virus.

Causes
Shingles is caused by varicella zoster virus (VZV), the same virus that causes chickenpox. After a person recovers from chickenpox, the virus stays dormant (inactive) in their body. The virus can reactivate later, causing shingles. Most people who develop shingles have only one episode during their lifetime.

Signs and symptoms
Shingles causes a painful rash that may appear as a stripe of blisters on the torso. Pain can persist even after the rash is gone (this is called post-herpetic neuralgia).

Investigations
Polymerase chain reaction (PCR) is the most useful test for confirming cases of suspected zoster sine herpete (herpes zoster-type pain that occurs without a rash). PCR can be used to detect VZV DNA rapidly and sensitively, and is now widely available.

Complications
Complications from shingles can include:
Postherpetic neuralgia. For some people, shingles pain continues long after the blisters have cleared. This condition is known as postherpetic neuralgia, and it occurs when damaged nerve fibers send confused and exaggerated messages of pain from your skin to your brain.
Vision loss. Shingles in or around an eye (ophthalmic shingles) can cause painful eye infections that may result in vision loss.
Neurological problems. Depending on which nerves are affected, shingles can cause an inflammation of the brain (encephalitis), facial paralysis, or hearing or balance problems.
Skin infections. If shingles blisters aren’t properly treated, bacterial skin infections may develop.

Differential diagnosis
The differential diagnosis for HZ includes herpes simplex virus, impetigo, candidiasis, contact dermatitis, insect bites, autoimmune blistering disease, dermatitis herpetiformis, and drug eruptions.

Management
Several antiviral medicines—acyclovir, valacyclovir, and famciclovir—are available to treat shingles and shorten the length and severity of the illness. These medicines are most effective if you start taking them as soon as possible after the rash appears.