Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder that primarily affects the joints, causing pain, swelling, and stiffness. This systemic disease can extend beyond the joints to impact other systems, including hair health. The link between RA and hair thinning is complex and multifaceted. Hair loss can result from the condition itself, the chronic stress of living with a long-term illness, or the medications used to manage the disease. Understanding these specific mechanisms is the first step toward finding effective management strategies.
How RA Inflammation Causes Hair Thinning
The systemic nature of rheumatoid arthritis means that chronic inflammation circulates throughout the body, driven by immune signaling molecules called cytokines. This persistent inflammation can disrupt the normal cycle of hair growth, causing hair follicles to prematurely enter a resting phase. The hair growth cycle consists of a growing phase (anagen), a transitional phase (catagen), and a resting phase (telogen) before the hair sheds.
An inflammatory state can trigger a condition known as telogen effluvium, where a large number of growing hairs are abruptly pushed into the shedding phase. This typically results in generalized hair thinning across the scalp, rather than distinct bald patches. The physical and emotional stress associated with managing a chronic illness like RA can also exacerbate this process, leading to increased shedding. This type of thinning is usually temporary and reversible once the inflammation or stressor is controlled.
Hair Loss Due to RA Medications
Medications used to treat RA are frequently the primary cause of hair loss, with certain drug classes known to interfere with hair follicle function. Methotrexate (MTX), a widely prescribed disease-modifying antirheumatic drug (DMARD), is the most common pharmaceutical culprit. MTX works by acting as a folate antagonist, blocking the body’s use of the B-vitamin folate, which is necessary for rapid cell division. Since hair follicles are among the fastest-dividing cells in the body, this mechanism disrupts their growth, leading to hair thinning or loss. The hair loss is diffuse, not patchy.
Doctors often prescribe folic acid or folinic acid supplements alongside MTX to counteract this folate antagonism and mitigate side effects, including hair loss, without reducing the medication’s effectiveness. Other DMARDs, such as leflunomide, have also been associated with hair thinning.
Biologics, which are newer treatments that target specific parts of the immune system, are less commonly linked to hair loss than traditional DMARDs. Long-term use of corticosteroids, sometimes used to manage RA flares, can also indirectly affect hair health by altering overall hormonal balance.
Related Autoimmune Conditions
RA patients are susceptible to developing other autoimmune conditions due to shared genetic and immune pathways, and some of these conditions specifically target hair follicles. Alopecia areata, a separate autoimmune disorder, is characterized by the immune system directly attacking the hair follicles, resulting in distinct, smooth, round patches of hair loss. While RA does not directly cause alopecia areata, the two conditions can coexist.
Other co-occurring autoimmune disorders, such as Hashimoto’s thyroiditis, can also contribute significantly to hair thinning. Autoimmune thyroid disorders disrupt hormone production, and the thyroid hormone is necessary for regulating the hair growth cycle. Addressing these related conditions is often a necessary step in diagnosing the true cause of hair loss in a patient with rheumatoid arthritis.
Steps for Addressing Hair Loss
The first and most important step in managing hair loss is consulting both a rheumatologist and a dermatologist to accurately identify the root cause. A doctor may order blood tests to check for nutritional deficiencies, such as iron or vitamin D, or to assess thyroid function, all of which can contribute to hair loss. If a medication is suspected, the rheumatologist may suggest adjusting the dosage or switching to an alternative treatment, such as a different DMARD or a specific biologic that is less likely to cause hair loss.
Patients should never stop taking their RA medication without a doctor’s guidance, as uncontrolled inflammation can lead to irreversible joint damage and worsen overall health. For MTX-related hair loss, increasing the folic acid supplement dosage can often resolve the issue. Lifestyle adjustments, including stress-reduction techniques and ensuring adequate nutrition, also support healthy hair growth by reducing systemic stressors and providing necessary building blocks for the hair follicle. Topical treatments, such as over-the-counter minoxidil, may also be recommended by a dermatologist to stimulate hair regrowth.