Chicken Pox

Its been a long long time since I updated my blog. I confess to the fact that I did lose interest in blogging. Good news is - I'm back! The reason for this particular subject, is because my sister texted me two days back - describing some symptoms that my baby brother was suffering from, and wanted to know if it pointed to chicken pox.

Chicken pox, is another name for Varicella - named after the culprit, Varicella Zoster Virus (VZV) and rarely also called Human Herpes Virus - 3 (HHV-3), because it belongs to the herpes virus family.

* Inetersting History - My decision to write about Chicken Pox, was accompanied by an interest in "why the name chicken pox?". Its strange, but this is what wikipedia told me: Small pox was discovered before chicken pox was. And hence, it was not simply considered a different disease on its own, but rather a milder form of small pox - and therefore a "chicken" form of small pox (meaning not as dangerous). The other reasons are a little silly. One being, because the lesions look like the skin was pecked by chickens and that the lesion were similar to a chick pea (I dont see the similarity). A not so believable one is that it was derived from an old English term "giccin" (does that sound like "chicken" to you?) which means "itching". And in the medieval times, the term "pox" meant "curse". So they considered chicken pox to be a plague brought by a black magic curse.

Chicken pox is highly infectious. You can get the infection from an infected person either by direct contact or by inhalation of droplets in the air (when the infected person coughs or sneezes). The infection can also spread through the fluid inside the lesions, and thats usually how you might spread it from one part of the body to another.

Once you get infected, it takes around 10 to 14 days to show any signs or symptoms (in some cases, upto 21 days). The disease is more common in children, but can affect adults. However, in adults the disease has more severe manifestations. A point to be noted, is that once you get chicken pox, you develop life-long immunity to it. This means that once you get chicken pox, you wont get it again (with the exception of certain immuno-compromised conditions).

The disease starts with a low-grade fever, cough, sore throat (sometimes mistaken for common cold or flu), headache, weakness and in some children abdominal pain. Around 1 to 2 days later, the child develops a rash which usually starts on the head and the trunk and spreads to the rest of the body. The rash is known to be highly pruritic (or itchy).

The rash is known to appear in crops. A lesion follows through a series of stages before it dies off. It starts as red macule (a flat area of discoloration - in this case red), and then becomes a papule (a raised lesion) and then a vesicle (raised lesion filled with clear fluid) and later a pustule (raised lesion with pus). The end stage of the lesion is when it crusts and then heals. Healing is usually without scarring, but it may leave a scar if the child scratches the lesions and causes it to rupture. The vesicle stage of the rash is described as a "pearl or dewdrop on a rose petal" appearance, because the fluid filled lesion sits on top of a reddish background. The hallmark of the rash, is that fact that you always see multiple stages of the lesion on the body at the same time. A new lesion takes upto 6 days to crust. And new crops continue to erupt for upto 3 to 5 days.

Remember that an infected person can transmit the infection starting from 2 days before the rash until all the skin lesion crust. Its hard to tell chicken pox before the rash appears (unless you know that your child was exposed - maybe a classmate had it few days back). But, the parents are advised not to send their children to school to avoid contact until all the lesions have crusted (this usually takes one week).

There is no treatment. You just allow the disease to take its course. It is usually self-limiting (unless you are immuno-compromised, or under steroid therapy or you have another disease). You can always get a prescription for a topical cream or ointment to reduce the itching. And it is very important that the patient does not scratch the lesions! I have heard of parents who cover their kids' hands either with a mitten or even just a plastic bag, to prevent them from scratching. It is also important that the child is provided with a healthy diet with sufficient hydration.

Chicken pox can have serious complications (usually in immuno-compromised conditions). It can cause varicella encephalitis or varicella pneumonia, both of which are highly fatal and can cause death. You may also need special treatment if the lesions get superinfected with bacteria (happens when the lesions are scratched - infection spreads from dirty nails and hands). Also, pergnant women must be extra careful, because varicella infection has very serious effects on the fetus.

There is a vaccine which has been developed against varicella. Its efficacy is found to be between 70% to 90%.