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.
Secondary Hyperhidrosis Causes. Sweating from secondary hyperhidrosis is different from primary hyperhidrosis in that it tends to happen all over or in one general area instead of on the hands, underarms, face, or feet. Unlike primary hyperhidrosis, this type is more likely to cause sweating during sleep. And in this case, there is something thatâs causing hyperhidrosis: a medical condition or a medication. A number of medical conditions have the potential to cause hyperhidrosis.