Coal Tar for Psoriasis

After my first psoriasis flare in elementary school, I was sent home from my doctor’s office with a tub of smelly yellow cream to apply to my legs. At the time I had no idea what psoriasis was, or what was in that magic tub, but eventually my spots went away and I all but forgot about that cream. Fast forward a few decades and I now know that the not-so-magic ingredient was coal tar. That cream, Exorex, was my first experience with coal tar, but I’ve been regularly using coal tar for many years now and I still love the stuff.

What is coal tar?

Coal tar is a by-product of the cooking process of coal. When coal is heated to high temperatures it liberates by-products like coal tar. This process can be used to produce other types of “tar” that have also been used therapeutically. Wood tar, shale tar, and petroleum tar are three additional examples. Of these three, the most common is pine tar (sometimes referred to as “pine pitch”), which is a wood tar produced by heating high resin wood like pine or juniper. All four types of tars are generally prepared at 1-3% for psoriasis treatments and are considered one of the safest ways to topically treat psoriasis.

How can coal tar improve psoriasis?

Coal tar is doubly effective for treating psoriasis because it has anti-inflammatory properties and anti-scaling properties. It is “keratolytic”, meaning that it breaks down keratin and can therefore soften and break up plaques; another popular keratolytic is salicylic acid. It also inhibits overproliferation of skin cells making it effective in treating psoriasis. Unlike topical steroids, coal tar has little effect on unaffected/normal skin, which makes application easier and less damaging to surrounding skin. This is great for those of us with guttate psoriasis or with no time for judicious application!

How do you use coal tar?

The most common way to use coal tar is a prescription or OTC preparation. Cream and shampoo preparations are very popular for psoriasis patients. Coal tar brands include Denorex, T/Gel, MG217, Exorex, Polytar, and Psoriderm. We also featured a pine tar lotion called “Mom’s Stuff Pinion Salve” in our Spring 2017 Favorite Things article, which is made with wild-harvested pine pitch. Tar shampoos are usually applied by working the solution into your scalp and letting sit for 5 minutes before rinsing out; some lotions will similarly instruct to be rinsed. Be sure to follow the instructions!

Combining coal tar with phototherapy

When combined with phototherapy, coal tar treatment is referred to as Goeckerman therapy. Developed in 1925, the Goeckerman regime involves the application of a tar preparation followed by phototherapy. While effective for many psoriasis sufferers, the popularity of this treatment has declined in recent years due to the advent of new biologic therapies and the overall inconvenience; after all, slathering up for 2 hours and chilling in a light box for weeks on end, day after day, leaves much to be desired!

Possible coal tar side effects

The biggest concern cited for coal tar use is an increased risk of cancer. However, aside from the Goeckerman method, there is little concrete evidence that supports this (especially at the concentrations found in OTC preparations). That being said, it’s important to discuss this (and other side effects) with your doctor. Any tar can also stain clothing and hair at high concentrations, and some individuals find it irritating to their skin. Always do a spot test before going wild! If you are using other topical medications (like steroids or vitamin D analogues), check with your doctor to assess potential interactions. Lastly, you should avoid getting concentrated coal tar in sensitive areas, and be aware that it can increase photosensitivity. Oh yeah, and it smells (…like RELIEF!).

Fun coal tar tips
My first coal tar tip would be to find an OTC that also contains menthol (like my Denorex shampoo, for example). Not only do you get the coal tar benefits, but the menthol has a cooling sensation that helps relieve itching. I have also found that moving your coal tar shampoo to one of those condiment squeeze bottles with the nozzle tip helps for application in the shower. It’s easy to apply it along your hairline and gets it right on the scalp without losing 80% in your hair. Try applying to your hair part, rub it in, then flip over the next section of hair and re-apply until you’ve covered your whole scalp. My last tip would be to think outside the shampoo/lotion box and check out some coal tar bath oils. I much prefer soaking in the tub to standing around in the shower, so baths can be an innovative way to increase contact time.

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