|"Is this all real? Or has this been happening inside my head?"
The topic of this article is of a real-life subject that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really exists), and, as such, details contained in this article may differ from real world facts.
Chicken pox is a highly contagious viral infection. It usually starts with skin rash, mainly on the torso and head rather than the extremities, and becomes itchy and raw pockmarks, which mostly heal without scarring.
A subject who has had chicken pox has the virus in a dormant form in the body's nerve tissues, but it can be reactivated in later life in a different form known as shingles (herpes zoster).
In 1938, Billy Stubbs and Eric Whalley developed chicken pox at Wool's Orphanage. Mrs. Cole, the matron, told one of her helpers to take the iodine to Martha, so that she could disinfect their pockmarks.
- Harry Potter and the Half-Blood Prince (Mentioned only)