I was out hiking in the Marin Headlands yesterday and noticed huge growth of poison oak everywhere due to the exceptionally wet Winter & Spring. For outdoor adventurers, be sure to get familiar with what poison oak looks like before hiking. Here's a good pic of our local species: poison oak. It is similar to poison ivy and poison sumac. While not everyone reacts to poison oak, those that do, develop varying levels of symptoms consisting of skin rash and itching. Rash may consist of redness, edema or swelling, and blistering. It is a reaction to direct contact with the substance urushiol which is contained on the leaves of the plant. Urushiol can spread directly via animals and clothing. It can also spread through the air from burning poison oak. Poison ivy and poison sumac also produce urushiol. Small localized rashes may be resolved quickly with hydrocortisone cream, a corticosteroid, which may be bought over the counter. Corticosteroids should be avoided by diabetics, those who are allergic, and perhaps when infection is present. Topical application of corticosteroids can cause skin changes, including discoloration, so it is best to avoid over the counter steroid creams on the face. For large rashes causing much itchy misery, or for rashes causing significant swelling of the face, lips, mouth or throat, or groin, oral prednisone or even injectable steroids may be needed. For rashes associated with shortness of breath or severe lightheadedness or fainting, call 911 or get yourself quickly to an ER. For fast symptomatic relief of itching, diphenhydramine (Benadryl) may be used by most people. This is bought over the counter in the form of tablets or cream. The cream should only be used on small localized rashes, not large rashes, because it can cause toxicity if too much is absorbed. Some folks also experience itch relief using calamine lotion, oatmeal or baking soda baths. Urushiol is quickly absorbed through the skin, so it is best to immediately wash with grease removing soap and copious repeat water rinse, or rinse with rubbing alcohol. Your pharmacist can tell you about the latest options effective for removing urushiol from skin, such as Technu, which should still be used even after the initial wash and rinse as described above. Don't forget to wash your clothes and pets too. Occasionally, poison oak rashes may develop bacterial infection requiring antibiotic treatment.