<s>[INST] My two year old had a blue black blister type spot at the top of her anus this afternoon. It is no longer there but she does smell a lot in that area - I am missing something but not sure what. She has woken once or twice every night this week and is often hot. Her poo is generally very hard. [/INST] Hi, If I were your treating Doctor for this case of blister, I would come up with such possibilities, these include: the lesions as vesicles is more consistent with Herpes; the best diagnostic methods include a scraping, tincture (called Track) and viral culture of the content of one of the lesions; serum antibodies for Herpes 1 and 2 can also be ordered, but, it is better to assess the lesion contents directly.1. Hot Bath: To a tub of lukewarm water add 2 spoons of antiseptic solution or baking soda. Sit in it immersing bottom for 15-20 minutes each session twice a day. The warmness will reduce pain and also help in Chat Doctor.   </s>