Red bumps- look like mosquito bites

I went swimming in a lake with some weird algae in it that you are supposed to kill in a pool when you get out but i didnt have time to get in the pool untill about 5 hours later. Then the next morning i woke up with about 20 mosquito bite looking bumps from my knees down. i know it cant actually be bites because i would have felt that many bites, so what is it??

[Bhupinder Kaur, MD]

Hello,
These bite like marks can be due to contact dermatitis, allergies or due to insect bites. You can take some antihistaminic like benadryl or Claritin. Although the rash may be itchy, avoid scratching it because you may damage the skin, and allow bacteria to get in, leading to infection. You may also need topical and oral steroids which are available under prescription. Also wear cotton clothes.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.