No..You are suffering from Photo dermatitis.. Medicine available for good improvement......As the treatment varies depending on the severity... Send photos of the affected area, for accurate diagnosis and treatment.

Soap is not any treatment. This description sounds like acanthosis nigricans. This is a condition where your skin​ folds like underarms, inner thighs or groin, neck and face becomes dark. It is either genetic or due to sedantry lifestyle and overweight. This can be treated. Please call me or contact me with photos using online consult option for proper diagnosis, treatment advice and prescription.