On the heels of the day-care colds came the shingles. Even as immunologist, I knew little about the disease. I knew it’s caused by the same virus as the chickenpox and manifests with a rash. I admit, I thought that is it – a rash. I had no idea how painful and dangerous it can be.
Shingles are caused by varicella zoster. The same virus that causes chickenpox. Only people who had chickenpox, can get shingles as the disease is not a fresh infection, but the awakening of virus sleeping within you.
Similar to the herpes simplex virus, varicella zoster is not completely killed and removed from your body during the initial infection (aka the chickenpox). Some virus remains and lives, in a dormant state, within nerve clusters close to the spinal cord. As long as your immune system is fully functional, it keeps the virus in check and prevents an awakening. If the immune system is, however, compromised, the virus can start to replicate and move down the arms of the nerve cells (called axons) to the area of skin innervated by the affected nerve cells. There, the virus causes local inflammation and the characteristic blistering rash.
Why does it hurt so much?
The rapid replication of the virus and its travel down the axons causes inflammation and stimulates/damages the nerve cells – which can cause severe pain. This pain can last weeks or even month longer than the varicella outbreak itself.
Once the rash subsides, the virus travels back up the nerve cells and irritates them again. One to two thirds of patients over 50 suffers from chronic pain after they had shingles. This is due to the damage the virus causes the nerve cells. If the pain remains longer than 90 days the condition is called postherpetic neuralgia.
Even if the damage is repaired and the pain could subside, your brain can trick you into thinking it is still there. This is called pain memory. If we experience a prolonged, strong pain we remember it, leading to potentially long lasting phantom pains. Anti-viral medication is therefore paired with pain medication during treatment of shingles. I had to take paracetamol for weeks after the infection started.
And why can it be dangerous?
Shingles is not a skin disease. It should be considered a neurological disorder. The close relation to nerve cells and the harm the virus does to the cells makes it dangerous. Not just because of the pain but other “side effects”. One of the worst examples is a varicella-induced meningitis which is an infection of the membranes surrounding your brain.
Most patients report the rash around their chest or abdomen. I went to the doctor because of swollen lymphnods and a massive headache. I had noticed the small rash on my face but did not think much of it. In the end I was lucky my doctor immediately referred me to a dermatologist.
Between 10-20% of shingles patients have a rash in or around the eye. This needs close monitoring and an aggressive therapy approach, as damage to the ophthalmic nerve can cause blindness. My rash spread for two days before the medication kicked in and, luckily, I was speared the hospital iv drug treatment. Facial paralysis and ear damage can also occur when the virus affects facial nerves.
Shingles are much more than the rash. I learned it the hard way – you read it here. But it is not all bad. Good news is, that in addition to the chickenpox vaccine, a stronger vaccineagainst varicella, which can prevent Shingles, is licensed for people over 50 years of age – the age-group where side-effects are the greatest. Given that one in three people in the USA will get shingles in their life, you should really get the vaccine.