You seem to have developed an irritant reaction to the prescribed medicine. This could be due to over zealous application of the drug or the medicine simply didn't suit to your skin type. Kindly withhold application of these creams for a while and apply a steroid
cream as well as soothing moisturiser. Once the redness
and itching subsides, the treatment for pigmentation can be re introduced. Consult a dermatologist
so that the pigmented area can be examined and further treatment be advised. Don"t lose heart, your skin will definitely improve. Take care.