What Is Post-Inflammatory Hyperpigmentation? Dark Marks, Causes & Treatment Options Post-inflammatory hyperpigmentation is flat residual discoloration that develops after skin inflammation or injury stimulates excess or misplaced melanin. It appears after problems such as acne, eczema, irritation, burns or

What Is Porphyria Cutanea Tarda? Fragile Skin, Blisters & Treatment Options Porphyria cutanea tarda is a porphyrin-metabolism disorder that makes sun-exposed skin unusually fragile and prone to blisters, erosions, slow healing and scarring. Reduced hepatic uroporphyrinogen decarboxylase activity allows

What Is Porokeratosis? Ring-Like Skin Lesions, Causes & Treatment Options Porokeratosis is a group of chronic keratinization disorders that produce expanding skin lesions with a narrow raised keratotic ridge surrounding relatively flatter or thinner central skin. Lesions can become

What Is Polymorphic Light Eruption? Sun-Triggered Rash, Causes & Treatment Options Polymorphic light eruption is a recurrent photosensitivity disorder that causes itchy or burning skin lesions several hours to one or two days after ultraviolet exposure. Also called polymorphous

What Are Plantar Warts? Foot Warts, Causes & Treatment Options Plantar warts are benign cutaneous HPV growths on the sole that often become rough, thick and inward-growing because standing and walking compress them into weight-bearing skin. Also called verruca

What Is Pityriasis Versicolor / Tinea Versicolor? Skin Color Patches, Causes & Treatment Options Pityriasis versicolor, also called tinea versicolor, is a common superficial yeast disorder caused by overgrowth of Malassezia that produces finely scaly lighter, darker or pink