Urushiol, is the rash-causing oil found in all parts of poison ivy, poison oak, and poison sumac plants. Approximately 85% of the population experiences an allergic reaction to these noxious plants, and according to the National Institute of Occupational Health & Safety, 50 micrograms of urushiol is enough to cause a rash in 80-90% of adults.
Sweaty palms, more properly known as palmar hyperhidrosis, is a condition that affects about 1% of the US population. Although the exact cause of sweaty palms is still debated, many experts believe it is caused by a hyperactive sympathetic nervous system, causing the sweat glands in the hands to produce sweat unnecessarily.
The most common cause of small bumps on the palms of the hands is something called dyshidrotic eczema. In this condition, the skin on the palms (or the soles of the feet) becomes irritated, and the initial symptoms are small firm blisters under the skin, about the size of a pinhead, which may be either whitish or clear in appearance.