i have poison ivy all over and some on my penis and scrotum. my penile foreskin is fat and huge and my scrotum

The rash (allergic contact dermatitis ) from poison ivy, oak, or sumac generally is mild and can be treated at home. Home treatment for the rash usually helps relieve symptoms but does not speed up healing of the rash.

If you know you had contact with one of these plants, immediately wash areas of the skin that may have touched the plant. Sometimes the rash can be completely avoided by washing the affected areas with plenty of water within 10 or 15 minutes of contact. You could also try using a product (such as Tecnu or Zanfel) that is designed to remove the oil from your skin.
To relieve itching and help dry blisters, apply wet compresses or soak the area in cool water. Antihistamine pills or calamine lotion may help relieve symptoms.
If you have a moderate to severe rash, you may need to see your doctor. He or she may prescribe corticosteroid pills. These medicines may help improve or clear up the rash more quickly. Prescription corticosteroid creams, ointments, gels, or shots may also be used.
A frequent complication of the rash is infection. If this occurs, your doctor will probably prescribe an antibiotic cream that you spread on the affected skin if the infection is small. Otherwise, you may need antibiotic pills or a shot. To prevent infection, try not to scratch the rash. Cut your fingernails short to minimize the possibility of opening the skin and spreading bacteria.

Regardless of what type of treatment is used after a rash develops, the length of time it lasts will vary from person to person.