Pyrazinamide-induced phototoxicity: A rare and underrecognized adverse effect

Abstract Tuberculosis (TB) is a communicable airborne disease caused by the bacterium Mycobacterium TB. Pyrazinamide (PZA) is a unique anti-TB (anti-TB) drug that plays a key role in shortening TB therapy. PZA kills nonreplicating persisters that other TB drugs fail to kill, which makes it an essential drug for inclusion in any drug combinations for treating drug-susceptible and drug-resistant TB, such as multidrug-resistant TB. The most common adverse reaction related to this drug is hepatotoxicity. Hyperuricemia is also another common adverse effect, resulting from the inhibition of uric acid excretion by the kidneys, which can lead to the development of gout in patients. Other adverse effects, such as arthralgia, flushing, rashes, fever, and loss of diabetes control, may be seen. Rarely, PZA may cause phototoxicity. The most frequent drugs causing phototoxicity are vemurafenib, voriconazole, doxycycline, hydrochlorothiazide, amiodarone, and chlorpromazine. This case report highlights a rare adverse effect of PZA, specifically phototoxicity that occurs in areas exposed to sunlight. The unusual nature of this reaction makes the case particularly noteworthy.