Researchers propose identifying TMP-SMX hypersensitivity reactions as SCoRCH: JAMA

TMP-SMX hypersensitivity reaction ranges from circulatory shock to aseptic meningitis and respiratory failure and is a potentially life-threatening condition having dermatologic relevance.

Madeleine O'Brian, University of Texas Southwestern Medical Center, Dallas, and colleagues in their study have proposed that TMP-SMX hypersensitivity reaction be identified as SCoRCH (sudden conjunctivitis, rash, and lymphopenia combined with hemodynamic changes). This is considering the clinical and mucocutaneous features of TMP-SMX hypersensitivity reactions that are distinct from those of other drug reactions and are potentially life-threatening.

The authors addressed the question, "what are the clinical features and mucocutaneous findings of an increasingly recognized hypersensitivity reaction associated with hemodynamic changes after using trimethoprim-sulfamethoxazole?"

The study was a retrospective case series study of 7 patients who developed hemodynamic changes, a characteristic rash, and end-organ dysfunction after treatment with trimethoprim-sulfamethoxazole at an extensive university hospital system from January 2013 to March 2022.

The cohort consisted of seven patients (median age, 20 years; 4 female and three male).

The study led to the following findings:

• The most common mucocutaneous findings were generalized sunburn-like erythema without scale, conjunctivitis, and mild facial and acral oedema.
• Three patients had previous exposure to TMP-SMX and developed symptoms in 1 day or less, while those without exposure presented from 4 to 11 days after drug initiation.
• Among the seven patients, six had a fever, 7 had hypotension, and 7 had tachycardia.
• All patients had lymphopenia and evidence of end-organ dysfunction with either kidney or liver involvement. The median time to resolution was 72 hours.

"Our findings suggest that SCoRCH refers to sudden lymphopenia, conjunctivitis, and rash combined with hemodynamic changes, should be considered for the differential diagnosis of patients presenting with acute generalized sunburn-like conjunctivitis, erythema, hemodynamic changes, and systemic symptom in the setting of recent use of TMP-SMX," the researchers concluded.

About Trimethoprim-Sulfamethoxazole

Trimethoprim-sulfamethoxazole is a combination chemotherapeutic agent and a commonly used antibiotic. Adverse drug reactions happen in 6-8% of patients. The most common adverse reactions include mild gastrointestinal distress and cutaneous events, a wide range of haematological abnormalities have also been ascribed to TMP-SMX.

Reference:

O'Brian M, Rose EK, Mauskar MM, Dominguez AR. Sudden Conjunctivitis, Lymphopenia, and Rash Combined With Hemodynamic Changes (SCoRCH) After Trimethoprim-Sulfamethoxazole Use: A Case Series Study of a Hypersensitivity Reaction. JAMA Dermatol. Published online November 09, 2022. doi:10.1001/jamadermatol.2022.4657