Intradermal injection of methylene blue for the treatment of refractory pruritus ani.
OBJECTIVE
Idiopathic pruritus ani is a common perianal condition that can be refractory to diligent perineal care. We wished to evaluate the efficacy and side effects of intradermal methylene blue for the treatment of refractory pruritus ani.


METHODS
A prospective series of 49 patients with idiopathic pruritus ani, who had failed to improve with perineal care, were treated by a single surgeon. All patients received intradermal injections of methylene blue. Endpoints were patient symptom score, and complications (pain, dysaesthesia, skin necrosis, incontinence and anaphylaxis).


RESULTS
Symptoms improved in 96% and resolved in 57% of patients after one treatment. All four patients who had a second treatment became symptom-free. Seven patients noticed changes in continence, all resolved between 10 days and 6 weeks. Two patients were distressed by their decrease in their perianal sensation. There was no skin necrosis or anaphylaxis.


CONCLUSIONS
Treatment of refractory pruritus ani by intradermal injection of methylene blue is effective and generally well tolerated.
Department of Surgery, Christchurch Hospital, Christchurch, New Zealand.
A D
AD
Sutherland
I G
IG
Faragher
F A
FA
Frizelle
D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D002908:Chronic Disease; D003113:Colonoscopy; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007271:Injections, Intradermal; D008297:Male; D008751:Methylene Blue / Q000627:therapeutic use*; D008875:Middle Aged; D017060:Patient Satisfaction; D011446:Prospective Studies; D011538:Pruritus Ani / Q000175:diagnosis / Q000188:drug therapy*; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult
D008751:Methylene Blue