Herpes Zoster (HZ), commonly called shingles, is a distinctive syndrome caused by reactivation of varicella zoster virus (VZV), which also causes chickenpox. Most people get chickenpox during childhood, a fact that prevents them from getting it again when they’re adults. However, our body does not eliminate the virus completely- the virus establishes a lifelong latent infection, remaining dormant in our body, eventually reactivating at a later stage .
Reactivation of VZV usually occurs as a result of weakening of the immune system due to aging or a damaged immune system. Children may also develop shingles, however the risk of getting shingles increases when as you get older, usually at the age of 60 or older.
The development of technology in the modern era has contributed to our understanding of various diseases mechanisms and drug development methods. In addition, post clinical epidemiological research highly contributes to our understanding of whether a current treatment is efficient and to what extent.
Turns out that a study found that the reactivation of VZV is associated with the use of certain drugs, such as methotrexate and certain biologic medications .
I bet your next question might be, “What is Methotrexate?” Well, good question! Methotrexate is a medication used to treat certain types of cancer such as breast, skin, head and neck, or lung, as well as severe psoriasis and rheumatoid arthritis . According to Medline Plus, Methotrexate may decrease the activity of the immune system, and as a result develop serious infections . Which actually may be the reason to the reactivation of VZV I mentioned, though the actual reason for reactivation was not discussed in the study.
In actual fact, Psoriasis and rheumatoid arthritis are a chronic inflammatory disorders of the immune system [5-6], in which the body actually attacks itself. This causes a problem: on the one hand, there is a need to regulate and control the immune system, and on the other hand, if the immune system is too down regulated, the body won’t be able to fight latent infections. Therefore, this study results suggest the need for a vaccination against VZV in patients with psoriasis and various risk factors for shingles.
1. CDC.gov – “Shingles (Herpes Zoster)” – Prevention & Treatment. Last Reviewed on May 1, 2014.
2. Family Practice News – Methotrexate and biologics linked to higher zoster risk in psoriasis. Published on March 22, 2015.
3. Drugs.com – Methotrexate. Last revised on January 6, 2015.
4. Medline Plus – Methotrexate. Last revised May 15, 2014.
5. Psoriasisconnect.com – Psoriasis and your immune system.
6. Shah, Ankur. Harrison’s Principle of Internal Medicine (18th ed.). United States: McGraw Hill. p. 2738.