Topical minoxidil, used in the treatment of baldness, has been commercially 
available since 1987. Its systemic side effects are rare. We observed an as yet 
unreported "polymyalgia syndrome" in four otherwise healthy males whose sole 
medication was topically applied minoxidil. They experienced fatigue, weight 
loss and severe pain in the shoulders and pelvic girdle, suggesting connective 
tissue disease. Three patients had a transient rise in liver enzymes, while 
other laboratory analyses remained normal. Tritanomaly was detected in two 
patients who underwent systematic color vision testing. All symptoms disappeared 
after withdrawal of minoxidil. Rechallenge was positive once in one patient and 
twice in another. The mechanism of this side effect remains to be determined.