Rare Skin Conditions

Urticaria pigmentosa (UP) is a rare disease that affects the skin and occasionally other parts of the body. UP is a type of mastocytosis (also known as mastocytoma), which affects a sub-type of immune cells known as mast cells. UP is characterised by skin lesions and itching. Mast cells are formed in the bone marrow from pluripotent stem cells, under the influence of stem cell factor (SCF).


Actinic Prurigo (AP) is a rare chronic, idiopathic skin condition, which is characterised by abnormal cutaneous responses to ultraviolet radiation (i.e. photosensitivity). AP is thought to be mediated by an abnormal immune response in the background of genetic predisposition. AP is a rare condition and is usually seen in certain populations of the Americas.