PT - JOURNAL ARTICLE AU - Hanne Yri AU - Marianne Wegener AU - Rigmor Jensen TI - Syphilis mimicking idiopathic intracranial hypertension AID - 10.1136/bcr.09.2011.4813 DP - 2011 Nov 09 TA - BMJ Case Reports PG - bcr0920114813 VI - 2011 4099 - http://casereports.bmj.com/content/2011/bcr.09.2011.4813.short 4100 - http://casereports.bmj.com/content/2011/bcr.09.2011.4813.full AB - Idiopathic intracranial hypertension (IIH) is a condition of yet unknown aetiology affecting predominantly obese females of childbearing age. IIH is a diagnosis of exclusion as raised cerebrospinal fluid pressure may occur secondary to numerous other medical conditions. An atypical phenotype or an atypical disease course should alert the physician to reevaluate a presumed IIH-diagnosis. The authors report a case of a 32-year-old non-obese male with intracranial hypertension, secondary to a syphilitic central nervous system infection, initially misdiagnosed as being idiopathic. Upon relevant antibiotic treatment, signs and symptoms of elevated intracranial pressure resolved completely. Syphilis is a rare, but very important, differential diagnosis that in this case was clinically indistinguishable from IIH.