A 17 year-old male (height: 1.803 m; weight: 83.235 kg; body mass index (BMI): 25.59 kg/m2) high school varsity athlete (football, basketball) was referred to an outside endocrinologist by his primary care provider after an approximate 2-year history of worsening episodes of exercise-induced excessive sweating accompanied by abdominal cramps, headaches, dizziness, occasional blurred vision, and paresthesia throughout his entire body during exercise. His sweating episodes were characterized by a heavy increase in sweating approximately 5 min after the onset of athletic activity. A complete general medical and endocrine evaluation was inconclusive. His comprehensive metabolic panel was within normal limits. His physical examination was unrevealing. The patient subsequently presented to our sports medicine clinic for evaluation of heavy sweating during athletic activities.
Subjective hyperhidrosis (HH) is a reasonably common clinical complaint, but frequently patients are found to have a normal sweat rate when tested. The first step in our clinical protocol for most patients who complain of excess sweating is to have them exercise in a hot and humid environment and measure their weight pre- and post-workout to get an estimate of their actual sweat rate. This patient ran for 33 min on a warm and humid afternoon (88 F, humidity 65%, heat index 97.5), did not urinate, and demonstrated a 3.2-kg weight loss which calculated to an estimated sweat rate of 5.8 L/h (69.9 mL/kg/h). Following this period of exertion, he had a normal resting heart rate at 70 beats per minute. His sweat pattern appeared normal with sweat noticeable on his head, chest, back, and all four extremities. Post-exertional labs were obtained within 5 min of exercise completion and demonstrated mild acidosis (CO2: 21; anion gap: 19), hyperphosphatemia (5.9 mg/dL), and hyperglycemia (123 mg/dL), but no other electrolyte or acid-base abnormalities. We discussed with the patient and his family the results including the excessively high rate of sweat loss (69.9 mL/kg/h vs normal rate of 10-20 mL/kg/h). We encouraged aggressive fluid resuscitation with sugar and electrolyte sports during prolonged exercise athletic events and continued abstinence from caffeine. We also discussed with the patient the possibility of using an aluminum hydroxide-based antiperspirant diffusely over his body in an attempt to limit the rate of sweating during athletic competitions.
Given the patient's athletic participation, we also made a plan with the patient to test how glycopyrrolate therapy might alter his body temperature and sweat rates during strenuous physical activity. We obtained institutional review board (IRB) approval (the project was deemed exempt) and informed verbal consent from the patient's father and verbal assent from the patient for a research protocol to test the patient's physiologic response to glycopyrrolate therapy when physically stressed in a hot and humid environment.