Coal forms from the accumulation of plant debris, usually in a swamp environment. When plant debris dies and falls into the swamp the standing water of the swamp protects it from decay. Swamp waters are usually deficient in oxygen, which would react with the plant debris and cause it to decay.
Porokeratosis is generally considered to be a benign condition though malignant transformation has been seen in all but the punctate variety, necessitating regular followup of patients with porokeratosis (Maubec et al., 2005; Sasson & Krain, 1996).
Excessive sun exposure may cause the development of porokeratosis. Porokeratosis is a common skin condition. Exposure to artificial UV light, such as the type used in tanning beds, correlates with porokeratosis. As porokeratosis spreads, a person may start to experience fever and fatigue.It's important for porokeratosis patients to wear sunscreen while outdoors, regardless of the weather.t is possible to have a single lesion or multiple abnormal spots on the body. Lesions typically do not change in size and shape over time, and any changes that do occur can be signs of developing skin cancer. Skin carcinomas that arise due to porokeratosis are usually characterized by hard, scaly, dark-colored lesions.