When people come in contact with poison ivy, the urushiol can cause an allergic skin reaction that produces reddish, itchy, and painful inflammation of the skin (dermatitis). Close relatives of poison ivy plants that produce similar dermatitis symptoms are poison oak and poison sumac.
Health conditions that may cause excessive sweating include: 1  Diabetes. 2  Endocarditis. 3  Fever of undetermined cause.  Generalized anxiety 1  disorder. Hiatal hernia.  Heat 1  exhaustion. HIV/ 2 AIDS. Hyperhidrosis.  Hyperthyroidism (overactive 1  thyroid) 2  Leukemia.  Malaria.
In most cases however, excessive head sweating is a chronic problem that is caused by an overactive sympathetic nervous system for which there is little known cause. There are also a number of factors that may trigger excessive sweating including heat, anxiety, stress and other emotional reactions such as anger. Keep cool. Wear loose fitting and light clothing which allows your skin to breathe. Cotton and linen are great, but avoid synthetic fabrics and silks whenever you can.