Is it okay to be on treatment medications before a scalp biopsy?
I’m often asked if being on medications will make a difference to the 'accuracy' of a scalp biopsy for hair loss. After all, if one is looking for a certain finding (such as inflammation) and the drug is supposed to help remove that finding (such as inflammation)... wouldn’t being on the drug be a bad thing?
Overall, this tends to be a complex question and not as simple as one might think. In general though, it is preferable for a patient to NOT be on any type of anti-inflammatory treatment before his or her scalp biopsy.
In typical well-developed cases of scarring alopecia being on treatment will not affect the diagnosis but could affect the accuracy if determining the degree of inflammation in the skin and therefore the overall activity of the scarring alopecia.
In other words if the question is “is this a scarring alopecia? - being on treatment usually won’t alter that answer in a well developed case. However if the question is “is this scarring alopecia mildly active, moderately active or severely active?” - being on treatment could alter that interpretation.
The challenge comes with diagnosing early staged scarring alopecias. Here, we are talking about the subtle cases. Here we are talking about the cases that don’t look like scarring alopecia. Here we are talking about the cases whereby a patient has itching, burning, pain or shedding and everyone including the patient’s family, friends, neighbour, hairdresser and sometimes even physician is telling them they will be fine.
In these subtle cases, being in treatment is not a good idea.
The key finding in early LPP is inflammation centred in the upper follicle and inflammation causing death of keratinocytes in the hair follicle. Treatments such as topical steroids, steroid injection and oral immunomodulators (doxycycline, hydroxychloroquine, etc etc) can reduce this inflammation. But one needs to keep in mind that scarring alopecia is not only about inflammation - it’s about oil glands and scar tissue as well. Well-developed scarring alopecia shows disappearance of sebaceous glands which is not going to be affected by these immunosuppressive treatments. One must also consider the experience of the dermatopathologist reading the biopsy. It’s a huge huge deal. A very experienced dermatopathologist can sort through alot of these subtleties - an inexperienced dermatopatholigist sometimes can’t sort through these as easily.
I’m a big fan of analogies. If you consider for a moment your life as a plumber and being called to an old apartment building. The man renting the apartment thinks there is a leaky pipe in the roof because he has heard sounds of water dripping for days and days. He phoned the owner of the apartment who came in for 2 minutes carrying a box of bandages and tape and did something in the ceiling and now the dripping noise has stopped.
In cases of a tiny leak or early problems, this use of bandages and tape (ie the “treatment”) may be enough to stop the leak. After the tape is applied, it’s difficult now for the plumber really tell if there is a problem. The plumber can see the tape on the pipes when he looks up in the roof but it’s hard for him to say if there is really anything wrong. Maybe the tape was put there before? Phrased another way, the “treatment” done by the owner makes it challenging to know if anything is wrong with the pipe right now and whether the apartment is really under any sort of risk for flooding. When the plumber is asked “Is their a problem with the pipe or not?” ... the plumber is not sure. Treatments clearly make a difference to how we evaluate things in the case of early problems.
Now consider if you would a well developed leak. In a “well developed” pipe leak, there will be water everywhere! The floor may be stained with water stains. If the leak has gone on long enough, the room may smell and there may even be mold growing. Even if the pipe is fixed (ie treatment administered) it’s still very easy to tell there was a flood. Now when the plumber is asked “Is their a problem with the pipe or not?” he can say there was certainly a problem somewhere. The plumber is sure there is a plumbing problem and sure there was a leak. Treatment generally makes little to no difference to the final evaluation: Yes, there was a leak.
To summarize, it’s not ideal for a patient to use oral or topical treatments if one is trying to rule out a challenging case of early staged disease. If one tries to “fix” things before a biopsy is done .... it can be difficult to confidently determine if there was a problem. In well developed disease, it makes little difference. Overall, a patient using topical, injection or oral immunosuppressive treatment has the potential to have an altered interpretation of their biopsy... mainly a low risk of a “false negative” in cases of diagnosing early-staged disease. For most however, it’s only a “potential” (relatively small) risk.
Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887