Seasonal variation of Stevens-Johnson syndrome and toxic epidermal necrolysis associated with trimethoprim-sulfamethoxazole

J Am Acad Dermatol. 2009 Apr;60(4):589-94. doi: 10.1016/j.jaad.2008.11.884. Epub 2009 Feb 13.


Background: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare and severe cutaneous adverse reactions to medications and infections.

Objective: We sought to determine whether a seasonal variation to SJS and TEN exists and to define the characteristics in our tertiary referral hospital.

Methods: A retrospective chart review of 50 patients from 1995 through 2007 was performed and statistically analyzed.

Results: The most common medication implicated as a cause of SJS/TEN was trimethoprim-sulfamethoxazole (TMX) (26%). A seasonal trend, favoring springtime, was observed for the total number of cases of SJS and TEN (P = .34). There was a significant increase in cases due to TMX (53%) occurring in spring compared to other seasons (P = .002). These patients were significantly younger (37.8 +/- 13.7) than other patients with SJS and TEN (53.7 +/- 16.4) (P = .003). Their overall mortality (1 death) and average SCORTEN value (1.62 +/- 1.6) was also significantly lower (P = .04 and 0.03, respectively). Based on outpatient pharmacy records, there was no increase in TMX prescriptions filled during the spring.

Limitations: The study was limited by reliance on chart data, the use of inpatient records, and number of patients.

Conclusions: A seasonal variation in SJS and TEN caused by TMX affecting younger patients may exist.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Infective Agents / adverse effects*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Retrospective Studies
  • Seasons*
  • Stevens-Johnson Syndrome / chemically induced*
  • Stevens-Johnson Syndrome / etiology*
  • Trimethoprim, Sulfamethoxazole Drug Combination / adverse effects*
  • Young Adult


  • Anti-Infective Agents
  • Trimethoprim, Sulfamethoxazole Drug Combination