With the ongoing cold and dry weather, skin disorders are coming up. With uncontrolled use of cosmetics, allergies to cosmetic products are on the rise too. Patch testing is done for cosmetic products such as PPD and metals like nickel, chromium and various other chemicals. TYPES OF DERMATITIS: Contact Dermatitis: Contact dermatitis is when an… Continue reading Dermatitis and Skin Disorders. Skin allergy patch testing.