Hi, I can understand your concern for rash under the armpit that has a itchy leaky fluid. There can be multiple possibilities of the itchy red bumps on butt and private parts and it requires a close physical examination to diagnose the exact entity of the problem. In my view correlating with the facts you have provided it appears to be allergic dermatitis or fungal infection of the area. I suggest you to meet a dermatologist to for proper therapy. In between you should wash the area properly. If I were your dermatologist then presumptively would have preferred to apply an antifungal cream such as clotrimazole or miconazole. You can take an antihistamine such as loratadine for once a day if itching is present. Do not try to pinch, pop or squeeze the area as it may cause secondary infection of the area. All the best