Sudden conjunctivitis, lymphopenia, and rash combined with hemodynamic changes (SCoRCH) is a hypersensitivity reaction with hemodynamic changes that occurs in response to trimethoprim-sulfamethoxazole (TMP-SMX) exposure. It is also known as TMP-SMX-induced circulatory shock, and anaphylactic-like, or severe shock-like, reaction to TMP-SMX. Pathogenetically, a T-cell mediated immune response with subsequent rise in interleukin 6 (IL-6) is posited, although the exact mechanism is unknown. This systemic reaction to TMP-SMX was first described in patients with HIV, but more recent cases have been reported in people without HIV infection.

The hallmark mucocutaneous manifestations of SCoRCH include conjunctivitis, generalized erythema, and mild acral and facial edema. The eruption may be pruritic. These findings are accompanied by tachycardia, and hypotension and shock requiring vasopressors may be seen. Fever is commonly associated. Acute kidney injury and transaminitis may be present, and lymphopenia is common. Aseptic meningitis and respiratory failure have been reported as isolated reactions to TMP-SMX as well as in the setting of SCoRCH.

In people with no prior exposure to TMP-SMX, onset occurs 4-11 days after drug exposure, but in those with a history of TMP-SMX exposure, onset can occur within 1 day of re-exposure.