Low Dose Isotretinoin for Seborrheic Dermatitis: Is it an option for tough to treat cases?

Isotretinoin 2.5 mg to 20 mg for Refractory Seborrheic Dermatitis.

Seborrheic dermatitis (SD) is a common, chronic skin disorder that typically affects 5% of the adult population. The exact pathogenesis of SD is still not entirely clear but many issues may be relevant including Malassezia colonization, patient predisposition to immune or inflammatory reactions, hormone levels, sebum production, and lipid composition on the skin surface.

Isotretinoin may be helpful in treating SD. It reduces sebaceous gland size by decreasing proliferation of basal sebocytes, suppresses sebum production up to 90%, and prohibits sebocyte differentiation.

Yanfei et al, 2023

Authors from China recently set out to retrospectively analyze the efficacy and safety of oral isotretinoin in the treatment of patients with moderate to severe seborrheic dermatitis. All included patients were diagnosed as having moderate to severe seborrheic dermatitis and were treated with oral isotretinoin from January 2019 to December 2020.

A total of 48 patients with moderate to severe SD were part of the study. 26 patients were treated with oral isotretinoin at a dose of 20 mg/day, and 22 patients were treated with oral isotretinoin at a dose of 10 mg/day. The duration of treatment was 2.42  0.98 months (range: 2–6 months).

Symptoms of SD reduced with use of oral isotretinoin and there was no difference between the 10 mg and 20 mg groups.  90% of patients were moderately or well satisfied with the two treatment schemes, and the difference was not statistically significant.

Side effects included  cheilitis in 47 of 48 patients followed by  skin fragility (face 23/48, body 21/48), nose fragility (7/48), pruritus (5/48), nosebleeds (4/48), muscle aches (3/48), headache (3/48), and eye problems (2/48). Abnormal serum lipids were noted in (13/ 48).

Conclusion

All in all, the authors included that low dose isotretinoin can be beneficial in moderate to severe SD.

Two prior studies support the use of isotretinoin in SD and are important to be aware of:

Geissler et al 2003

A 2003 study set out to evaluate the benefits of very low doses of isotretinoin in 11 patients over a 6 month period. The influence on seborrhea was measured during oral treatment with 5 mg/d, 2.5 mg/d, or 2.5 mg 3x weekly. Sebum production was reduced by up to 64% and acne lesions regressed by as much as 84%.

In general, good results were achieved in all patients. The small number of patients did not permit a statistical analysis of the three isotretinoin doses studied. However, the authors point out that there was a tendency toward better results with the two higher doses.

Rademaker, 2017

The author performed a retrospective review of 46 patients (56% female) with seborrheic dermatitis treated with isotretinoin over a 5-year period. All patients had failed conventional treatment with anti-Malassezia and anti-inflammatory treatments.  Mean age was 26 years (range, 12-62 years). Forty patients also had some degree of acne vulgaris; 6 had concomitant rosacea, and 5 had scalp folliculitis. Patients were coprescribed 2% ketoconazole and 1% hydrocortisone cream, used as required. 

The starting dose of 20 mg isotretinoin/d was reduced in 33% of patients (to 10 mg/d or 10-20 mg, 3-5 times/wk) but was increased in 29% (to 30 mg/d in 20% and to 40 mg/d in 9%).   Treatment was continued for 33 weeks (range, 14-70 weeks). Seborrheic dermatitis treatment response was considered excellent (or cleared) in 41 (89%) patients. Twenty (43%) were still on treatment at the end of the study. In this study,  the most common side effect was cheilitis (43%), followed by nose bleeds (4 patients), increased skin fragility (3), tiredness (3), eczema (2), and 1 each of muscle aches, mood changes, eye problems, and haematuria. Adverse effects were reported more commonly in patients whose dose was increased to 30 to 40 mg/day.

REFERENCE

Yanfei Z  et al. Efficacy and safety of oral isotretinoin in the treatment of moderate to severe seborrheic dermatitis: a retrospective study. Int J Dermatol. 2023 Feb 15.

Geissler SE et al. Very low dose isotretinoin is effective in controlling seborrhea. J Dtsch Dermatol Ges. 2003 Dec;1(12):952-8.

Rademaker M. Low-Dose Isotretinoin for Seborrhoeic Dermatitis. J Cutan Med Surg. 2017 Mar/Apr;21(2):170-171.