All are impoant hypersensitivity related side effects of high dose sulfasalazine therapy, EXCEPT:

Although sulfasalazine is more effective at higher doses, up to 30% of patients experience allergic reactions or intolerable side effects such as headache, anorexia, nausea, and vomiting that are attributable to the sulfapyridine moiety. ALSO KNOW: Hypersensitivity reactions, independent of sulfapyridine levels, include rash, fever, hepatitis, agranulocytosis, hypersensitivity pneumonitis, pancreatitis, worsening of colitis, and reversible sperm abnormalities. Sulfasalazine can also impair folate absorption, and patients should be given folic acid supplements. Ref: Harrison, Edition-18, Page-2489.