Chicken Pox

A common childhood disease, chicken pox is caused by the varicella-zoster virus (VZV). Adults too can be afflicted by this self-limiting disease. Usually, a person is affected by chicken pox just once in a lifetime. However the virus can lie dormant in the body and surface later as shingles. It is essential to consult the doctor if the rash spreads to the eye or it is accompanied by disorientation and dizziness. Rare complications of chicken pox include viral pneumonia or encephalitis. There is a risk of a birth defect if a pregnant woman contracts chicken pox in the first trimester.

Chicken pox surfaces as red and itchy rashes on the skin. These blisters appear on the face, arms, abdomen, mouth, ears and scalp. Over time the rashes get filled with clear fluid. They break open in a few days to crust over and become dark and dry scabs. A person suffering from chicken pox also tends to suffer symptoms such as fever, headache, sore throat and abdominal pain. The symptoms are milder and the blisters are fewer when chicken pox affects children. Chicken pox is very contagious, especially in the first few days when the rash appears.

An episode of chicken pox lasts for a couple of weeks. Patients suffering from chicken pox usually do not require any medication. But they can be given cool baths to relieve itching. Calamine lotion when applied to the itchy areas can give relief. Children suffering from chicken pox must be given mild food that is easy on the digestion. The chicken pox vaccine is now given to prevent episode of chicken pox. This varicella vaccine is now part of the regular immunization schedule for children.

Shingles

Shingles (Herpes Zoster) is a viral infection caused by Varicella zoster virus. It is the same virus that causes chicken pox. Shingles can develop in anyone who has had chicken pox. The chicken pox virus often remains dormant in the body's nerve root cells. It may surface years later in the form of shingles. It is likely to occur when the body is weak or stressed or immune defenses are low. Shingles is not a contagious condition nor does it lead to cold sores or genital herpes.

Shingles appear as painful blisters. Shingles rashes appear as a cluster of raised red dots on one side of the body. They become filled with fluid and later dry out and form a crust. There is severe pain and sensitivity. Typically these painful blisters appear to affect one part of the body. There may be itching and tingling feeling on the skin before the shingles rashes appear. In cases of shingles where the eye is affected, it is essential to consult an ophthalmologist immediately. A patient suffering from shingles may notice fever and headache.

Calamine lotion can be applied to affected areas to soothe the skin. Analgesics or NSAIDs can help in reducing pain. Antiviral medications are often prescribed for shingles. An attack of shingles might last for about a month.

Herpes Zoster Ophthalmicus

Herpes zoster ophthalmicus  HZO, also known as Ocular Shingles, is a painful dermatomal rash around the eye region and forehead caused by the reactivation of the Varicella Zoster Virus (VZV). It affects the trigeminal nerve of the ophthalmic division and eventually spreads to the other structures of the eye. The first division of the trigeminal nerve is the most common site for the development of acute herpes zoster.

Varicella-zoster virus manifests at two different stages in humans. At primary level the virus causes chicken pox after which it remains dormant for several years and reappears as herpes zoster later in the patient’s life. Aging, poor nutrition and low immunity are some of the risk factors that leads to the outbreak of Herpes zoster ophthalmic us (HZO).

Symptoms

HZO begins with flu-like symptoms including fever, Myalgia, and malaise for nearly a week. Typically, patients then develop tingling sensation and painful rash on the forehead and ocular symptoms such as eyelid edema; conjunctival, episcleral and circumcorneal conjunctival hyperemia; corneal edema and light sensitivity. All these symptoms are unilateral - occurring on one side of the face. 

Diagnosis

Herpes zoster ophthalmicus (HZO) is diagnosed clinically by mere observation of the symptoms. During a clinical visit, the ophthalmologist conducts a detailed examination of  visual acuity, visual fields, extra ocular movements, pupillary response, corneal function, Intraocular Pressure and anterior chamber. Doctor also makes a note of past history of chicken pox infection along with clinical examination. Viral culture, direct immunofluorescence assay, or Polymerase chain reaction (PCR) may also be used to confirm the diagnosis. Any signs of Hutchinson disease strongly indicates ocular complications such as inflammation and corneal denervation and forms the basis for diagnosis of herpes zoster ophthalmicus.

Treatment

Herpes zoster ophthalmicus is a medical emergency and should be treated promptly to avoid vision loss. The disease leads to many ocular conditions such as dermatitis, corneal pseudo-dendrites, uveitis, retinitis, and in rare cases it also causes cranial nerve palsies. Oral anti viral medicines like Acyclovir and Famcyclovir play a major role in treating herpes zoster ophthalmicus. Atropine eye drops are also prescribed to alleviate the painful symptoms. In case keratitis develops, Corticosteroid drops along with Cycloplegics (eye drops to induce ciliary muscle paralysis) may also be considered.