A patient presents to the clinic with a chief complaint of an inability to sweat.
It was a telemedicine visit, so all communication was done via video. We don’t get too many issues with sweating, so I was initially caught a bit off guard and confused. But long story short, the patient reported an encounter with some molds years ago that he believed damager his nerves, and ultimately led to a complete loss of sweating. He had some testing done in another city confirming that he lost all sweating ability with the exception of a small part on his neck.
One cause of this could be autoimmune, meaning his own his immune system had attacked his eccrine (sweat producing) glands of his body. One disease similar to this is Sjogren’s syndrome, where the body attacks lacrimal glands and ducts of the body leading to dry eyes, dental cavities from dry mouth and sometimes painful sexual intercourse from vaginal dryness. The first screening test for autoimmune disease is to measure titers of antinuclear antibodies. This is a very sensitive test meaning that if the test is negative, we can rest assured you don’t have an autoimmune disease. Reciprocally, if you test positive, it’s not guaranteed that you’ll have an autoimmune disease. Our patient had pretty high antibody titers (1:320) meaning the test was positive, so more specific antibody tests were performed. For these specific antibody tests, having a positive test would give us high suspicion for a particular autoimmune disease. Unfortunately, none of the specific antibody tests that were performed tested negative, leaving us in the dark with regards to a diagnosis. The suspicion for autoimmune disease must have been high since he was offered corticosteroids at this point in an attempt to shut down his immune system with hopes that this would halt or possibly reverse the sweat gland damage. The patient told me that he declined this offer due to the myriad side effects that corticosteroids present. Fair enough.
Guidelines have been published for the classification of anhidrosis or the absence of sweating (shown below). Following the chart, at the first bifurcation we can go down acquired since he didn’t have this at birth. After extensive workup, no clear source was identified as causing the anhidrosis, so we go towards idiopathic. And since the loss of sweating was nearly systemic, we can call this acquired idiopathic generalized anhidrosis, which is just fancy talk for acquired loss of sweating everywhere and without an identifiable cause.
Unfortunately treatment for acquired idiopathic generalized anhidrosis isn’t too exciting. Since this is a rather rare disorder, it becomes difficult to perform large clinical trials and since the target audience is small, pharmaceutical companies are likely to move on to bigger diseases. This leads to the disease being understudied, and leads the physician without a robust arsenal of treatments.
A proposed treatment algorithm is shown below from the same paper. Essentially the most important thing is to council the patient on lifestyle changes to prevent heat stroke. Since the body relies on sweating to cool down the core temperature, removal of this function can cause an individual to be susceptible to overheating. Such preventive measures include “avoiding hot environments, limiting exercise and cooling their bodies (e.g. proper use of air conditioning, wearing a cooling vest and carrying bottled cold water).” The use of steroid therapy is probably controversial, but our patient didn’t want it anyways, so we didn’t offer it again. It would be nice to be able to perform a biopsy to see what was happening to the sweat glands under the microscope, and possibly come up with alternative therapies based on what we saw. But since this occurred during COVID times, the patient refused to come into the clinic. So overall very interesting case, very unsatisfying treatment.