Darkening of the skin after using Antiderm XL Ointment is often due to irritation or the steroid component in the cream, which can alter skin colour and sometimes worsen underlying infections, especially fungal ones, so it is best to stop using this ointment and avoid self-medication in this sensitive area. Keep the area clean and dry, wear loose cotton underwear, and consult a doctor (preferably a dermatologist) who can examine you and prescribe the correct treatment, usually a specific antifungal or other appropriate medicine based on the cause, and in most cases, the darkening improves gradually once the correct treatment is started and the irritant is stopped.