You must be having fungal infection. Fungal infection tends to affect folds of the skin, moist areas like groins, armpits, mouth, genitals, under the breasts, webs between fingers and toes, etc. Our skin protects us from fungal/yeast attack, but any cut or break in the continuity of the skin can allow penetration of fungus. It gives rise to rash, eruptions, redness, burning, intolerable itching and abnormal discharges at times. Fungal infection tends to last for many years if not treated well. It is also contagious