Efficacy and safety of methylene blue injection for intractable idiopathic pruritus ani: a single-arm metaanalysis and systematic review.

PURPOSE: To evaluate how effective methylene blue injection was at treating intractable idiopathic pruritus ani. METHODS: A comprehensive literature search of the PubMed, Embase, Cochrane library, and Web of Science databases was conducted. All clinical studies (prospective and retrospective) that evaluated the efficacy of methylene blue in treating intractable idiopathic pruritus ani were included. Studies that reported the resolution rate, after a single injection and after a second injection, the recurrence rate, symptom scores, and transient complications of methylene blue injections in treating intractable idiopathic pruritus ani were included. RESULTS: The seven selected studies included 225 patients with idiopathic pruritus ani. The resolution rates after a single injection and after a second injection was 0.761 (0.649-0.873, P < 0.01, I2 = 69.06%) and 0.854 (0.752-0.955, P < 0.01, I2 = 77.391%), respectively, the remission rates at 1, 3, and 5 years were 0.753 (0.612-0.893, P < 0.001), 0.773 (0.675-0.871, P < 0.001) and 0.240 (0.033-0.447, P < 0.001), respectively, the effect value of the merger was 0.569 (0.367-0.772, P < 0.001, I2 = 79.199%), and the recurrence rates at 1, 2, 3, and < 1 year were 0.202 (0.083-0.322, P < 0.001), 0.533 (0.285-0.781, P < 0.001), 0.437 (-0.044, 0.917, P < 0.001) and 0.067 (0.023-0.111, P < 0.001), respectively. The effect value of the merger was 0.223 (0.126-0.319, P < 0.001, I2 = 75.840). CONCLUSION: Using methylene blue injections to treat intractable idiopathic pruritus ani is relatively efficacious, resulting in a relatively low recurrence rate and no severe complications. However, the available literature was of poor quality. Therefore, higher quality studies are necessary to confirm that methylene blue injection is efficacious for pruritus ani, such as a randomized prospective multicenter studies.

Long-term follow-up of intradermal injection of methylene blue for intractable, idiopathic pruritus ani.

BACKGROUND: While various medical treatments such as topical steroid ointment, antihistamine agent, and sedatives have been used for treating idiopathic intractable pruritus ani, they are not long-term solutions, due to the high recurrence rate. The aim of this study was to determine the effect of methylene-blue intradermal-injection therapy for treating patients with idiopathic intractable pruritus ani. Symptom improvement and recurrence rates were determined with a long-term follow-up. METHODS: A retrospective study was conducted from January 2011 to October 2013 on consecutive patients with intractable pruritus ani treated with methylene-blue intradermal injection. The therapy included 5 ml of 1% methylene blue and 15 ml of 1% lidocaine. Follow-up included a physical exam and satisfaction-score survey (1 = much worse, 2 = worse, 3 = no improvement, 4 = much better, 5 = gone completely) before treatment, 6 weeks after treatment, and 3 years after treatment to check patient status and recurrence rate. RESULTS: Of 103 treated patients, 96 were able to attend the 6-week follow-up visit. There were 58 (60.4%) males and 38 (39.6%) females with a mean age of 48.34 ± 10.21 years. Their mean satisfaction score at 6 weeks was 4.23 ± 0.86. Of the total of 96 patients, 9 (9.4%) patients scored 3 or less in their satisfactions score at 6 weeks. 62 (64.6%) patients were evaluated 3-year post-treatment. The satisfaction score at 3 years after treatment was 4.74 ± 0.57. Besides the 9 patients who initially failed treatment, 4 of the remaining 53 patients scored 3 or less in their satisfaction score surveys. Thus, the recurrence rate at 3 years was 7.5% (4/53). CONCLUSIONS: Methylene-blue intradermal injection can result in a high symptom improvement rate with low recurrence rate for patients with idiopathic pruritus ani.

Pruritus ani.

Pruritus ani is an unpleasant cutaneous sensation that induces the desire to scratch the skin around the anal orifice. It may start insidiously and appears in 1% to 5% of the population. It is classified as primary (idiopathic) pruritus ani when no cause can be found. However, as 25% to 75% of cases have co-existing pathology, a detailed history and examination are necessary. The goal of treatment is asymptomatic, intact, dry, clean perianal skin with reversal of morphological changes. The management of pruritus ani is directed towards the underlying cause. If the diagnosis is idiopathic pruritus ani, the patients can still be managed with great success by eliminating of irritants and scratching, by giving general advice regarding hygiene and lifestyle modification and by using active treatment measures.

Pruritus Ani

Pruritus ani is an unpleasant cutaneous sensation that induces the desire to scratch the skin around the anal orifice. It may start insidiously and appears in 1% to 5% of the population. It is classified as primary (idiopathic) pruritus ani when no cause can be found. However, as 25% to 75% of cases have co-existing pathology, a detailed history and examination are necessary. The goal of treatment is asymptomatic, intact, dry, clean perianal skin with reversal of morphological changes. The management of pruritus ani is directed towards the underlying cause. If the diagnosis is idiopathic pruritus ani, the patients can still be managed with great success by eliminating of irritants and scratching, by giving general advice regarding hygiene and lifestyle modification and by using active treatment measures.

The Effect after Intra-dermal Methylene Blue, Hydrocortisone, Lidocaine Injection Therapy for Intractable, Idiopathic Pruritus Ani

PURPOSE: Idiopathic pruritus ani is a common and embarrassing proctological condition which can be very difficult to treat. In this study, we documented our results with methylene blue intra-dermal injection in patients with intractable idiopathic pruritus ani. METHODS: 5-ml 1% methylene blue, 100-mg hydrocortisone, and 15-ml 1% lidocaine were injected into the perianal skin of 21 patients with idiopathic pruritus ani which had proved refractory to standard care. Clinical follow-up was undertaken. RESULTS: After one injection of the above solution, 15 (71.4%) of the patients were rendered symptom free. Repeat injection in the initial non- responders ultimately rendered another four. 19 (total: 90.5 %) of the patrents symptom free. Morbidity was 0%. CONCLUSION: This study has shown that intra-dermal methylene blue injection is a safe, simple, and efficient method of treating intractable, idiopathic pruritus ani.