Tar melanosis is an occupational dermatosis that occurs among tar handlers after several years of exposure, characterized by a severe widespread itching that is soon followed by the appearance of reticular pigmentation, telangiectases, and a shiny appearance of the skin. : 858

See also
Skin lesion


== References ==
It is not a life-threatening disease, and it is not contagious.Dermographism may occur in mastocytosis (systemic mast cell proliferation). Diagnosis
This condition is diagnosed by a health care provider writing or drawing on the patients skin with a tongue depressor or other implement, to see whether a red wheal appears soon afterwards. Treatment
Dermographism can be treated by substances which prevent histamine from causing the reaction (i.e. an antihistamine). These may need to be given as a combination of H1 antagonists, or possibly with an H2-receptor antagonist such as cimetidine. Over-the-counter vitamin C, 1000 mg daily, increases histamine degradation and removal.Refraining from taking hot baths or showers may help if the condition is generalized (i.e. all over), as well as possibly for localized cases (i.e. in a specific area). If taking hot showers helps, it may be a condition called shower eczema. If it affects mainly the head, it may be psoriasis. In rare cases, allergy tests may uncover substances the patient is allergic to.While cromoglycate, which prevents histamine from being released from mast cells, is used topically in rhinitis and asthma, it is not effective orally for treating chronic urticaria. See also
Triple response of Lewis

References


== External links ==