A review of the use of hyperthermia in the treatment of psoriasis.

Grade C

Hyperthermia (high temperature) therapies have a long history of use in dermatological conditions, including psoriasis. Whatever method is used, be it a hot-water bath, a dry heating pad, ultrasonics, etc., hyperthermia seems to provide good, if short-lived, remission of psoriasis symptoms with a minimum of side effects. This is mostly a review of the medical literature on hyperthermia from study abstracts available on Medline.

In 1980, a study titled “Response of chronic psoriatic plaques to localized heating induced by ultrasound” found that by using ultrasound to uniformly heat plaques to 42 to 45°C (107 to 113°F) for 30 minutes three times weekly, the plaques would go into remission. Only 9% of the plaques tested had no response, while 58% vanished completely. Biopsies of the psoriatic skin were compared, and some fundamental changes were apparent early on. It was noted that the psoriatic skin came back with three months.

In 1981, a study titled “Hyperthermia in the treatment of psoriasis” compared hyperthermia (in the form of chemical heating pads, commercially available) to the Goeckerman regimen and to simple occlusion with a non-heating pad. Skin temperature under the heating pads was raised to around 108°F (they don’t mention for how long, daily), and they found that it took only 61% as long for complete remission as for Goeckerman’s, on average (27 days). The researchers report that hyperthermic remission lasted as long or longer than the remission provided by Goeckerman’s regimen, with no apparent side effects.

In 1983, a study titled “Inhibition of a Langerhans cell-mediated immune response by treatment modalities useful in psoriasis” showed that hyperthermia and anthralin were both toxic to Langerhans cells (which stimulate parts of the immune response in psoriatic skin), while not being toxic to skin cells themselves. Hyperthermia, steroids, methotrexate, and anthralin all also inhibited the “skin cell lymphocyte reaction” (a measure of immune response) in psoriasis, while several antibiotics and another type of anti-inflammatory did not.

In 1984, a study titled “Human psoriatic skin lesions improve with local hyperthermia: an ultrastructural study” examined psoriatic skin using electron microscopy after hyperthermic treatments, and found no “abnormal cells or structures” in the skin.

And in 1995, a study titled “Water bath hyperthermia is a simple therapy for psoriasis and also stimulates skin tanning in response to sunlight” reported on seven patients who were given water-bath hyperthermia, of unknown temperature or duration. Swelling and itching were reduced, and full remissions were affected in all but one patient (who happened to be on etretinate). The remissions lasted one to three months, and in a couple of cases, re-application of the water-bath hyperthermia was tried and found successful again. The only noticable side effect was that the skin which was soaked tanned much easier than skin which has not been soaked. At least one person on the Newsgroup has mentioned that any water soaking, for him, increased his rate of tanning, so this may be an affect of water soaked into the skin by itself, and not necessarily due to the temperature.

In conclusion, it seems that hyperthermia works in a large percentage of cases, at least for a couple of months at a time. Hot-water soaks and heating pads look to be cheap, viable alternatives to treat some people’s psoriasis (extreme or stubborn psoriasis may not be as easy to combat). Obviously, more study is required, as there is not a lot of research out there, nor is much of it well-controlled or done on a large number of patients. As always, talk these things over with your dermatologist, and be wary of skin photosensitization (and of course, be careful to not burn or scald yourself, as skin damage can lead to a worsening of psoriasis through Koebnerization).