Sudden Red Dots on Kids' Legs? Be Alert — These Are Not Mosquito Bites

Red dots suddenly appearing on your child's legs may look like mosquito bites but could indicate Henoch-Schönlein purpura or other conditions requiring medical attention. Learn the key differences.

Recently, children with red rashes on both lower legs have been visiting the clinic from time to time. Most rashes are petechial manifestations, painless and itchless, and the rash persists and does not fade after pressing.

In combination with the child's history of upper respiratory tract infection before the rash appeared, it is easy to diagnose “IgA vasculitis” (IgA vasculitis, IgAV), a name more familiar to everyone is “Henoch-Schönlein purpura”.

Many parents become nervous upon hearing the term “Henoch-Schönlein purpura”: “Doctor, is my child allergic to something that causes skin bleeding? Do they need to avoid certain foods or get allergy tests?”

Actually, Henoch-Schönlein purpura is an old term for the disease. Now more clinicians would refer to this disease as “IgA vasculitis”. This is a relatively common systemic vasculitis in children, with an incidence rate of (3-27)/100,000.

What is IgA Vasculitis?

IgA vasculitis is common in adolescents and children, usually caused by infections, which is not the same as the “food allergies” or “pollen allergies” we often talk about.

Literature indicates that about half of IgA vasculitis follows upper respiratory tract infections, especially those caused by Streptococcus infections. In addition, vaccinations and insect bites can also trigger it, but they are relatively rare.

Unlike the purpuric diseases of the blood system that many people worry about, it is usually a self-limited vasculitis episode. If early recognition can be achieved and close observation is maintained, most cases will gradually improve on their own. Moreover, allergy tests are usually not required.