Resorcinol’s resourcefulness in hidradenitis suppurativa

By Warren R. Heymann, MD, FAAD
March 22, 2023
Vol. 5, No. 12

Management of hidradenitis suppurativa (HS) is challenging, including medical and surgical approaches, which are often combined for best outcomes. Lifestyle changes, pain management, and emotional/psychiatric issues must be addressed. Therapeutic approaches include the use of topical therapies (clindamycin, dapsone, benzoyl peroxide, chlorhexidine), systemic antibiotics (doxycycline, minocycline, rifampicin, clindamycin, metronidazole), intralesional steroids, hormonal therapies (spironolactone, metformin, finasteride), and a wide range of immunomodulators/immunosuppressants (retinoids, methotrexate, cyclosporine) and biologic medications (tumor necrosis factor inhibitors, anakinra, anti-IL12/23, anti-IL-17). For mild or moderate HS disease (Hurley stages I and II), any safe, topical regimen that improves the quality of life is desirable. This commentary focuses on the expanding literature about the use of topical resorcinol 15% in HS.

Resorcinol has been used as a chemical peel since the 19th century and its use was popularized by Paul Gerson Unna. (1) Resorcinol [C₆H₄(OH)₂,1,3-dihydroxybenzene] is a phenol derivative with keratolytic, antimicrobial, and anti-inflammatory properties, the latter due to stimulation of prostaglandin E2. (2,3) After scattered case reports describing topical resorcinol for abscesses, Boer and Jemec were the first to perform a clinical trial utilizing 15% resorcinol for HS. Twelve women with Hurley stage 1 or 2 HS treated with topical resorcinol 15% and followed up for at least 1 year were reviewed. A 15% concentration was chosen because the agent is believed to be safe at < 20% concentration, but with HS, would be used in areas of occlusion. Patients rated the efficacy of treatment on global maximum pain of nodules and abscesses on a visual analogue scale (VAS) and by self-report of the mean duration (days) of a painful lesion. All patients experienced a significant decrease in pain as assessed by VAS and reported a reduction in the mean duration of the painful abscesses. Resorcinol caused desquamation in all patients, which was soothed by moisturization. Four of 12 patients developed a reversible brown discoloration The authors suggested that further trials were warranted to confirm these results. (2)

In an uncontrolled, prospective trial, Pascual et al evaluated 32 patients (mean age 35.9 years) with Hurley stage I and II disease, who were treated with 15% resorcinol twice a day for 30 days. The initial mean clinical size of the lesions was 13.8 mm, whereas the mean size in ultrasound images was smaller at 10.5 mm (P = .004). By days 7 and 30, the clinical size of the lesions had decreased significantly (to 8.4 mm and 1.2 mm, respectively [P < .001]). Similarly, size on the ultrasound image showed a significant reduction from baseline at day 30 (3.2 mm [P < .001]) but not at day 7 (8.9 mm [not statistically significant]). A clinical and ultrasonographic resolution was achieved in 21 of 32 lesions (65.6%) at day 30; however, 6 (18.9%) showed only clinical and not ultrasonographic resolution, and 5 lesions persisted both clinically and on an ultrasound image. Desquamation was experienced by 16 participants (50.0%), and brown discoloration was recorded in 5 (15.6%) patients. (4)

In an uncontrolled study of 61 patients with Hurley stage I and II HS treated with topical resorcinol 15% daily for 12 weeks, Molinelli et al demonstrated a significant reduction in pain and improvement of the Dermatology Life Quality Index. (3) In a subsequent study, Molinelli et al retrospectively assessed 134 patients with mild-to-moderate HS. Seventy-three patients (group A) received topical clindamycin 1% and 61 patients (group B) received topical resorcinol 15%. The efficacy and tolerability of topical 15% resorcinol versus topical 1% clindamycin in mild-to-moderate HS were compared at 12 weeks of treatment. Patients treated with resorcinol 15% showed a significant improvement in Hidradenitis Suppurativa Clinical Response, International Hidradenitis Suppurativa Severity Score System, and Pain Visual Analogue Scale score from baseline compared to patients treated with clindamycin 1%. Adverse reactions included mild irritation, desquamation, and brown pigmentation — none of the 34 patients interrupted therapy. The authors concluded that topical resorcinol 15% could be a valid alternative to clindamycin in the management of acute and long-standing HS, limiting antibiotic use and thereby antimicrobial resistance. (5) In a study of 32 HS patients, utilizing topical 15% resorcinol twice daily for 16 weeks, 68.8% (n = 22) of the patients achieved a clinical response with 46.9% (n = 15) and 21.9% (n = 7) showing complete and partial responses, respectively. (6) In a survey of 92 patients treated with 15% resorcinol for mostly mild-to-moderate HS, 78 (84.8%) would recommend the treatment. (7)

Topical 15% resorcinol has also proven to be effective in other members of the follicular occlusion tetrad, including dissecting cellulitis of the scalp (8) and a pilonidal sinus. (9) (Lower strengths of resorcinol have a long-standing history in treating acne.)

As noted in the previous studies, adverse reactions to topical 15% resorcinol are mild, manifesting as mild irritation, desquamation, and self-resolving brown hyperpigmentation. Resorcinol sensitization is rare with positive patch tests reported as infrequently as 1 in 1000 patch-tested patients. Barbaud et al reported 8 patients in whom generalized allergic manifestations occurred after the topical application of an anti-wart ointment containing resorcinol, with 4 of these patients developing urticaria and angioedema. (10) Ingestion of resorcinol may prove fatal (respiratory failure, metabolic acidosis) and may cause fetal demise (11, 12). Resorcinol should be avoided during pregnancy.

My resident attended the HS Society symposium where she learned about topical 15% resorcinol. Her resourcefulness led to my prescribing resorcinol for the first time — I hope my experience lives up to the results of the recent literature. I have many years of experience with “wonder” drugs — I wonder why they work in the manuscripts I read, but not for my patients. If effective, 15% resorcinol would be welcomed as a topical therapeutic approach for this maddening disease.

Point to Remember: Topical 15% resorcinol has been increasingly reported to be safe and effective for mild-to-moderate hidradenitis suppurativa. Should further studies confirm its value, there will be added benefits by limiting antibiotic use and antimicrobial resistance.

Our expert’s viewpoint

Dr. José Carlos Pascual
Dermatología
Hospital General Universitario de Alicante

Over the last decade, greater understanding of the pathophysiology of HS has led to an increase in the therapeutic arsenal for the management of this disease. Most drugs tested focus on moderate and severe cases, leaving aside patients in the earlier and milder forms. (12) The European guidelines suggest a useful treatment algorithm for general patient management. For a given patient, the severity of the inflammatory burden should be determined and, depending on the severity, treatments are then chosen.

Since the initial publication by Boer and Jemec, several studies have pointed to a benefit from the use of topical resorcinol 15%, although all of them with a low level of evidence. As there are currently no published randomized double-blind placebo control trials, the real efficacy of resorcinol cannot be determined. It is true that indirect data are available, mainly derived from patient reported outcomes and satisfaction studies, suggesting a possible benefit. On the other hand, if we consider isolated lesions (inflammatory nodules and abscesses) it should be remembered that they tend to improve spontaneously in 7-10 days. (13) Therefore, as with other lesions that can spontaneously involute, such as viral warts, it is more difficult to determine the real efficacy of treatments. In my opinion, the main factor that determines the success or failure of resorcinol is the choice of the patient and specifically the type of lesion to be treated. Ultrasound can be a useful tool to better determine the type of lesion to be treated. (14) I believe that resorcinol 15% should be reserved for the management of inflammatory nodules and abscesses, in isolation or as an adjunct to other systemic treatments such as the combination of rifampicin and clindamycin, tetracyclines, metformin, spironolactone, and others. It is unreasonable to think that this topical treatment will be helpful in the management of tunnels or scar areas. The regimen described by Boer and Jemec is still the most commonly used, consisting of daily application to the affected area and twice daily to specific lesions (nodules and abscesses). Dr. Boer suggests starting to apply resorcinol during the early stages of the flare, as patients are well aware of the prodromal symptoms of the onset of the flare, describing it as burning, pain or itching.

In conclusion, there are data suggesting the usefulness of resorcinol in the management of mild to moderate forms of HS. However, randomized double-blind placebo control trials are desirable to determine the efficacy and safety of resorcinol in HS.

1. Borelli C, Ursin F, Steger F. The rise of Chemical Peeling in 19th-century European Dermatology: emergence of agents, formulations and treatments. J Eur Acad Dermatol Venereol. 2020 Sep;34(9):1890-1899. doi: 10.1111/jdv.16307. Epub 2020 May 25. PMID: 32080904.

2. Boer J, Jemec GB. Resorcinol peels as a possible self-treatment of painful nodules in hidradenitis suppurativa. Clin Exp Dermatol. 2010 Jan;35(1):36-40. doi: 10.1111/j.1365-2230.2009.03377.x. Epub 2009 Jun 22. PMID: 19549239.

3. Molinelli E, Brisigotti V, Simonetti O, Campanati A, Sapigni C, D'Agostino GM, Giacchetti A, Cota C, Offidani A. Efficacy and safety of topical resorcinol 15% as long-term treatment of mild-to-moderate hidradenitis suppurativa: a valid alternative to clindamycin in the panorama of antibiotic resistance. Br J Dermatol. 2020 Dec;183(6):1117-1119. doi: 10.1111/bjd.19337. Epub 2020 Aug 9. PMID: 32579711.

4. Pascual JC, Encabo B, Ruiz de Apodaca RF, Romero D, Selva J, Jemec GB. Topical 15% resorcinol for hidradenitis suppurativa: An uncontrolled prospective trial with clinical and ultrasonographic follow-up. J Am Acad Dermatol. 2017 Dec;77(6):1175-1178. doi: 10.1016/j.jaad.2017.07.008. PMID: 29132852.

5. Molinelli E, Brisigotti V, Simonetti O, Sapigni C, D'Agostino GM, Rizzetto G, Giacchetti A, Offidani A. Efficacy and safety of topical resorcinol 15% versus topical clindamycin 1% in the management of mild-to-moderate hidradenitis suppurativa: A retrospective study. Dermatol Ther. 2022 Mar 12:e15439. doi: 10.1111/dth.15439. Epub ahead of print. PMID: 35278025.

6. Cordero-Ramos J, Barros-Tornay R, Toledo-Pastrana T, Ferrándiz L, Calleja-Hernández MÁ, Moreno-Ramírez D. Effectiveness and safety of topical 15% resorcinol in the management of mild-to-moderate hidradenitis suppurativa: A cohort study. J Dermatol. 2022 Apr;49(4):459-462. doi: 10.1111/1346-8138.16275. Epub 2022 Jan 4. PMID: 34984726.

7. Docampo-Simón A, Beltrá-Picó I, Sánchez-Pujol MJ, Fuster-Ruiz-de-Apodaca R, Selva-Otaolaurruchi J, Betlloch I, Pascual JC. Topical 15% Resorcinol Is Associated with High Treatment Satisfaction in Patients with Mild to Moderate Hidradenitis Suppurativa. Dermatology. 2022;238(1):82-85. doi: 10.1159/000515450. Epub 2021 Apr 22. PMID: 33887735.

8. Navarro-Triviño FJ, Almazán-Fernández FM, Ródenas-Herranz T, Ruiz-Villaverde R. Dissecting cellulitis of the scalp successfully treated with topical resorcinol 15. Dermatol Ther. 2020 May;33(3):e13406. doi: 10.1111/dth.13406. Epub 2020 May 3. PMID: 32285588.

9. Encabo B, Pascual JC, Romero D, Ruiz de Apodaca RF, Selva J, Jemec GB. Pilonidal sinus: clinical and ultrasonographic response to topical resorcinol 15. Br J Dermatol. 2016Nov;175(5):1103-1104. doi: 10.1111/bjd.14872. Epub 2016 Aug 11. PMID: 27423054.

10. Bulut M, Turkmen N, Fedakar R, Aydin SA. A case report of fatal oral ingestion of resorcinol. Mt Sinai J Med. 2006 Nov;73(7):1049-51. PMID: 17195897.

11. Duran B, Gursoy S, Cetin M, Demirkoprulu N, Demirel Y, Gurelik B. The oral toxicity of resorcinol during pregnancy: a case report. J Toxicol Clin Toxicol. 2004;42(5):663-6. doi: 10.1081/clt-200026966. PMID: 15462161.

12. Zouboulis CC, Desai N, Emtestam L, Hunger RE, Ioannides D, Juhász I, et al. European S1 guideline for the treatment of hidradenitis suppurativa/acne inversa. J Eur Acad Dermatol Venereol. 2015;29:619-44.

13. von der Werth JM, Williams HC. The natural history of hidradenitis suppurativa. J Eur Acad Dermatol Venereol. 2000 Sep;14(5):389-92. doi: 10.1046/j.1468-3083.2000.00087.x. PMID: 11305381.

14. Martorell A, Alfageme F, Vilarrasa E, Ruiz-Villaverde R, Romaní De Gabriel J, García Martínez F, Vidal D, et al. Ultrasound as a diagnostic and management tool in hidradenitis suppurativa patients; a multicentre study. J Eur Acad Dermatol Venereol. 2019;33:2137-2142.

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