My 21 month old daughter has a longitudinal ulcer on the inside of her labia minora . She points at her vagina and says ouwh. It smells fishy. I put 3% hydrogen peroxide on it and she cried for a few minutes and then the sting seemed to go away. She is going diaper less today as I am concerned moisture makes it worse. She has had a shower already and is always clean, so hygiene is not the issue. We think it cold be a fungal infection , but would that cause an ulcer? The area surrounding the ulcer is not red or inflamed. There is no oozing from the ulcer, it is dry and slightly yellowish and looks like raised skin. The ulcer is the size and shape of a pumpkin seed. I don t want to put diaper rash cream on it and would use tea tree oil or lavender oil if it wasn t in the sensitive location that it is in. Is this common in toddlers? her diet is clean; eggs, fruit, oats, yogurt, chicken and all organic with not preservatives or chemicals. Please advise.