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).
Disseminated superficial actinic porokeratosis (DSAP) is a rare, non-cancerous, non-contagious skin disorder. Disseminated means that it is widely spread, most likely over the front and lower arms and legs -- areas that are typically frequently exposed to sun over a period of time.Superficial means that DSAP occurs on the outer layer of the skin.orokeratosis means that these skin changes are seen as a variety of flat, thickened lesions with slightly raised rims. You can feel this flaky rim when running your hand lightly down the arms and legs. DSAP is a chronic disorder; it can be treated, but it cannot be cured.