Methotrexate induced hair loss: How commonly does it occur?

Does low dose methotrexate (10-25 mg weekly) cause hair loss?

Methotrexate can affect the hair in many ways. It can cause a telogen effluvium, anagen effluvium, hair breakage as well as pigmentation changes.

It’s still somewhat controversial as to how commonly methotrexate causes hair loss. Some studies have suggested that number is high and some studies have suggested the number is low. Other studies have suggested that it depends on the patient population in question.

For example, it’s often quoted that hair loss occurs in 1-3 % of those using methotrexate to treat arthritis although many rheumatologists when asked feel the number is closer to 5-10 %. It has been estimated that up to to 3-10 % of those who use methotrexate to treat skin psoriasis with experience hair loss from the drug.

Here are some important studies to note:

Study 1: Lukasik et al, 2019

A study from Poland set out to evaluate if low dose (immunomodulatory dosing) of methotrexate could increase the chances of hair loss. The researchers surveyed 68 patients treated with methotrexate at the Department of Dermatology of the Jagiellonian University in Cracow in the years 2015-2018.

29.4 % of patients reported increased hair loss after starting methotrexate.

STUDY 2: Kumar and Lokanath al, 2019

A 2019 study by Kumar and Lokanath set out to determine if patients with rheumatoid arthritis using methotrexate had greater rates of hair loss. The authors used a simple pull test to compared rates of hair loss by the pull test at the start of the study as well as at week 3, month 2 and month 3. The pull test results were compared to those from healthy controls.

98 methotrexate treated patients and 82 controls were enrolled in the study. Methotrexate treated patients were 85 % female; controls were also mainly women (90%). The mean number of hair in the hair pull test at the start of the study was 1.21+2.01 in patients vs 0.84+1.25 in controls. Patients using methotrexate showed a mean change in the hair count at 3 weeks, 2 months and 3 months of -0.29, -0.31 & -0.26 respectively.(which corresponds to a reduction in hair fall). In comparison healthy controls showed values of 0.31,0.11, 0.1 at the same follow up time points.

The overall conclusion of this study was that methotrexate did not increase the chance of rheumatoid arthritis patients to develop hair loss.

Study 3: Lalani et al, 2020

Lalani and colleagues conducted a systematic literature review and meta-analysis to estimate the prevalence of alopecia (as well as other issues) with MTX in rheumatic diseases. The authors identified 3,954 studies of which 10 of 20 randomized controlled trials reported the prevalence of alopecia. The prevalence of methotrexate induced hair loss was between 1.0% and 4.9%.

Other studies

Other non randomized studies have suggested that the proportion of patients experiencing hair loss from methotrexate may be around 15-20 %

A study by Harada and colleagues found that 16.7% of patients using  methotrexate (MTX) for the treatment of non-infectious uveitis developed hair loss.

A study by Robinson and colleagues found that 23% of patients using  methotrexate (MTX) for the treatment of inflammatory arthritis developed hair loss.

A study by Dyer and colleagues found that 20% of patients using  methotrexate (MTX) for the treatment of asthma developed hair loss.

Conclusion:

We still don’t have a clear number as to how commonly methotrexate causes hair loss. A number around 5 % seems to be the most common estimate. The reality is that many studies in the literature suggest that even higher estimates may be appropriate.

Reference

Lukasik A et al. The influence of methotrexate on hair loss while using immunomodulatory doses. Pol Merkur Lekarski. 2019 Feb 28;46(272):77-79.

Harada et al. Methotrexate Effectively Controls Ocular Inflammation in Japanese Patients With Non-infectious Uveitis. Front Med (Lausanne) . 2021 Nov 18;8:732427.

Lalani et al. Low-Dose Methotrexate and Mucocutaneous Adverse Events: Results of a Systematic Literature Review and Meta-Analysis of Randomized Controlled Trials. Arthritis Care Res (Hoboken). . 2020 Aug;72(8):1140-1146.

Robinson et al. Tolerability and Adherence Problems in Patients on a Stable Dose of Methotrexate: Results of a Multicentre Survey Musculoskeletal Care. 2016 Sep;14(3):152-5.

Dyer PD et al. Methotrexate in the treatment of steroid-dependent asthma. J Allergy Clin Immunol . 1991 Aug;88(2):208-12.