Hello, Your symptom is indicative of contact dermatitis: This can cause patches of thickened, scaly skin that may appear dark brown or purple on darker skin tones. You are advised not to touch, pick or scratch as doing so will only cause the infection to spread. Stay away from anything that triggers the symptoms like detergents, soap, metals or allergens, etc. Take care of your hygiene. Cold compress may be helpful. Take regular showers/bath. Keep skin hydrated, apply herbal moisturizers after bath. Do not keep the skin dry. You are advised to get clinically examined by a Dermatologist, get skin allergy test, skin test, skin biopsy done to detect any other underlying medical condition like psoriasis, Bowen s disease, etc. that may need urgent medical attention and management. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician