When treating Alopecia Areata there are two main strategies, either suppress the body’s immune system (steroids, immunosuppressants, the new JAK inhibitors) or stimulate the immune system in the skin surface. The latter approach is thought to divert the immune system away from the hair follicle to the skin surface, allowing the follicle to recover and start to grow hair again. This technique is known as contact immunotherapy and can be achieved used an irritant chemical like Dithranol, applied daily and rinsed off, or by using a weekly chemical called Diphencyprone to generate a more specific allergic reaction. This technique is particularly suited to alopecia patients who have multiple patches, where steroid injections are not practical. One of the nice things about this approach is that you are not lowering the immune system and this is a particular concern at the present time due to Covid 19. So what is involved?
Firstly, a patient needs to be “sensitised”.
This involves application of a 10p size area of the chemical at 2% strength usually to the inner aspect of the arm. After 2-4 days you will develop a small patch of allergic eczema at the site of application. You can calm this down with some topical steroid or it will settle within a few days. Once you have developed the eczema you are sensitised and your immune system is now primed to respond every time it comes in contact with this artificial chemical. We then use very diluted samples eg 0.001% DCP to generate a very mild irritation, itch and redness, that will last a few days.
Everybody is different and it may take a few weeks of experimenting with different doses to find the right strength for you. Once we have identified the right strength, we can train a family member or friend to apply this treatment at home on a weekly basis, providing you with a pack of all the necessary equipment and your own bottle of chemical.
So how effective is it? Well studies vary and just like all alopecia treatments not everyone will respond and it takes a minimum of 3 months to even see the start of hair growth and really you will need to commit to 6 months of treatment to see if it is effective for you. Around 40% will respond and this is very similar to response rates with steroids and immunosuppressants, with the exception of JAK inhibitors, which may be a bit higher. Whilst you may need a few appointments to start with and a kit and chemical every 3 months, this is quite a cost effective treatment and 6 months of DCP will cost less than a few weeks of a JAK inhibitor! If you are interested or if this has been suggested to you by your specialist but not available locally, then please get in touch or book an appointment.