Poison Oak

May 14, 2006

It is a test of your mettle as a forester to get up in the middle of the night to call owls, to weather winter storms checking road drainage and stream crossings, to wipe blue paint off your face when you mistakenly stand downwind, to be dirty, to run property line down 100% slopes, to crawl or throw yourself at old growth huckleberry and to run cruise lines through poison oak. These experiences are badges of merit. However, having chewed the field challenges of the "dirt" forester, I could do without the poison oak. Oh I suppose I could also do without the 100% slopes, but everything else I embrace and is balanced by the perfect spring days spent on gentle terrain in the woods.

When people find out I am the poster child for poison oak sensitivity, their first question is how can you be a forester here in poison oak country. A rigid multi step routine, supported by a type A personality and obsessive compulsive disorder generally keeps me poison oak free unless it is above shoulder height.

The culprit is a chemical called urushiol found in the sap of poison oak. Ironically, human bodies, which defend against urushiol, contract the aggravating symptoms, whereas the bodies of the 3% of humans that are "immune" do not defend against the chemical. According to Terry Kratwurst in her article on this subject in the June/July issue of Mother Earth News: "Within 15 minutes after you get the substance on you, it's carried into the dermis (the inner skin layer) and bonds with skin protein to form an antigen. The first time this occurs, nothing obvious happens- no one is "born sensitive" to urushiolÖ.But sooner or later most people's immune system develops some degree of distinct biological distaste for the urushiol spawned antigen. At that point, whenever the antigen's presence is detectedÖT-cells rush to the hated invader and attack, releasing chemicals that literally destroy the surrounding skinÖbetter known as poison oak dermatitis."

The most frustrating aspect of contracting symptoms is questioning the source. Since there is a lag of as long as 4 days from the time you encounter the chemical to the time symptoms manifest you can imagine the speculation. Was it the dog I petted three days ago? A perfect ending to this story would be a cure, but after having tried pharmaceuticals and homeopathic remedies there is no magic cure and unless I want to move to Nevada the only State entirely free of species containing urushiol I will live with it, buck up and stop complaining.

I welcome responses as well as ideas for future Tree Tips. You can also get an email version by contacting me at thembi@mcn.org.

Thembi Borras is a Registered Professional Forester living and working in Mendocino County, CA USA.