Autoimmune

Autoimmune hair loss occurs when the body’s immune system mistakenly attacks healthy hair follicles, leading to thinning or baldness. These conditions can affect men, women, and even children, and often result in hair loss patterns that range from patchy bald spots to widespread thinning. In this article, we will explore the types of autoimmune hair loss, their underlying causes, and scientific research on these conditions.

What is Autoimmune Hair Loss?

Autoimmune hair loss happens when the immune system, which is designed to protect the body from harmful invaders, mistakenly targets hair follicles as though they were a threat. This immune response can result in hair thinning, scarring, or complete hair loss, depending on the condition. Unlike other forms of hair loss, which may stem from hormonal imbalances or genetic predispositions, autoimmune hair loss is specifically related to immune system malfunctions.

Types of Autoimmune Hair Loss

1. Alopecia Areata

Alopecia areata is one of the most well-known autoimmune hair loss conditions. It occurs when the immune system attacks the hair follicles, causing them to shrink and drastically slow down hair production. This results in sudden, patchy hair loss, often in round or oval areas on the scalp or body.

The exact cause of alopecia areata is unknown, but it is believed to be related to both genetic and environmental factors. In some cases, hair may regrow on its own, but the condition can recur or progress to more severe forms, such as alopecia totalis (complete scalp hair loss) or alopecia universalis (loss of all body hair) (Petukhova et al., 2010).

2. Lupus (Systemic Lupus Erythematosus)

Lupus is an autoimmune disease that can cause hair loss as part of its systemic effects on the body. Hair loss in lupus can be non-scarring (reversible) or scarring (permanent). In non-scarring lupus, hair may fall out in clumps due to inflammation of the scalp, while scarring alopecia occurs when inflammation causes permanent damage to the hair follicles.

People with lupus often experience diffuse thinning rather than patchy baldness, and the severity of hair loss often correlates with the activity of the disease (Hoffman & Werth, 2002).

3. Discoid Lupus Erythematosus (DLE)

A subset of lupus, discoid lupus erythematosus primarily affects the skin and can cause permanent hair loss due to scarring. This condition manifests as red, inflamed patches on the scalp or other parts of the body, where the immune system’s attack leads to scarring that destroys hair follicles.

Hair loss due to DLE is typically permanent, as the hair follicles are unable to regenerate after the scarring occurs (Wenzel et al., 2005).

4. Lichen Planopilaris (LPP)

Lichen planopilaris is a rare autoimmune disorder that leads to scarring hair loss, primarily on the scalp. It is a form of lichen planus that affects hair follicles, causing inflammation and destruction of these follicles over time.

The condition results in progressive hair thinning and bald patches, often accompanied by itching, redness, and scalp discomfort. As a scarring alopecia, the hair loss caused by LPP is usually permanent and irreversible once follicles are destroyed (Assouly & Reygagne, 2008).

5. Frontal Fibrosing Alopecia (FFA)

Frontal fibrosing alopecia is a subtype of lichen planopilaris and is characterized by the slow, progressive loss of hair along the hairline and eyebrows. FFA primarily affects postmenopausal women and results in a receding hairline that can be permanent due to scarring.

Scientists believe that FFA is an autoimmune condition, though its exact cause remains unclear. Early diagnosis and treatment may help prevent further hair loss, but hair that has been lost due to scarring does not regrow (Mansouri et al., 2013).

6. Hashimoto’s Thyroiditis

Hashimoto’s thyroiditis is an autoimmune disease where the immune system attacks the thyroid gland, leading to hypothyroidism (an underactive thyroid). Thyroid hormones are essential for hair growth, and when their levels drop, it disrupts the hair growth cycle, leading to thinning or diffuse hair loss.

Hashimoto’s-related hair loss typically manifests as overall thinning rather than patchy bald spots. Proper management of thyroid hormone levels often helps in reversing this type of hair loss (Mori et al., 2016).

7. Graves’ Disease

Graves’ disease is another autoimmune condition that affects the thyroid, but in this case, it leads to hyperthyroidism (an overactive thyroid). Like Hashimoto’s, imbalanced thyroid hormone levels disrupt hair growth cycles, causing diffuse thinning across the scalp.

Although hair loss due to Graves’ disease is usually temporary and improves with the treatment of thyroid function, it can lead to significant shedding during active phases of the disease (Wikner et al., 2015).

8. Scleroderma

Scleroderma is an autoimmune disease that causes the hardening and tightening of the skin and connective tissues, including the scalp. This hardening can result in scarring that destroys hair follicles and leads to permanent hair loss.

There are two types of scleroderma that may cause hair loss: localized scleroderma (morphea), which affects specific areas of the skin, and systemic scleroderma, which affects internal organs as well as the skin. Hair loss caused by scleroderma is often permanent due to follicular damage from scarring (Siegfried et al., 1997).

9. Psoriasis

Psoriasis is an immune-mediated condition that primarily affects the skin, but it can also involve the scalp, leading to hair loss. Scalp psoriasis causes thick, scaly patches that can disrupt the hair follicles and lead to temporary hair loss.

In most cases, hair regrows after treatment for psoriasis, though severe or prolonged inflammation can sometimes lead to more permanent thinning (Nestle et al., 2009).

10. Sarcoidosis

Sarcoidosis is an inflammatory disease that can affect multiple organs, including the skin and scalp. When sarcoidosis affects the scalp, it can cause scarring alopecia, leading to permanent hair loss. Hair follicles are damaged by granulomas—clusters of immune cells that form in response to the disease.

Hair loss from sarcoidosis is typically irreversible if scarring occurs, but early intervention can help manage the symptoms and limit further hair loss (Roth et al., 2009).

Scientific Insights on Autoimmune Hair Loss

Research into autoimmune hair loss continues to reveal new insights into how and why the immune system targets hair follicles. Studies on alopecia areata, for example, have shown that specific immune cells, including T-lymphocytes, play a critical role in attacking hair follicles, leading to hair loss (Petukhova et al., 2010).

In diseases like lupus and lichen planopilaris, the immune system’s chronic inflammation damages hair follicles, eventually leading to scarring and irreversible hair loss. Researchers continue to explore therapies aimed at modulating the immune response to preserve hair follicles and promote regrowth in these conditions (Assouly & Reygagne, 2008).

Conclusion

Autoimmune hair loss encompasses a range of conditions that involve the immune system attacking hair follicles, leading to various patterns of hair thinning or balding. Some conditions, like alopecia areata or scalp psoriasis, may result in temporary hair loss, while others, such as lichen planopilaris or discoid lupus, cause permanent hair loss through scarring. Understanding the underlying mechanisms of autoimmune hair loss is crucial for developing effective treatments and improving outcomes for those affected by these conditions.

References:

• Assouly, P., & Reygagne, P. (2008). Lichen planopilaris: Update on diagnosis and treatment. European Journal of Dermatology, 18(5), 519-521.
• Hoffman, R. W., & Werth, V. P. (2002). Cutaneous lupus erythematosus: Understanding the autoimmune responses and implications for therapy. Journal of Clinical Investigation, 110(1), 27-30.
• Mansouri, B., Haig, L. J., & Fischer, G. (2013). Frontal fibrosing alopecia: An emerging epidemic. Australian Journal of Dermatology, 54(1), 1-8.
• Mori, K., et al. (2016). Hair loss and thyroid disease. Endocrine Journal, 63(10), 903-912.
• Petukhova, L., et al. (2010). Genome-wide association study in alopecia areata implicates both innate and adaptive immune responses. Nature, 466(7302), 113-117.
• Roth, W. J., et al. (2009). Sarcoidosis and scarring alopecia: A case series. Journal of the American Academy of Dermatology, 60(1), 59-64.
• Siegfried, E. C., et al. (1997). Scleroderma syndromes: Evolving concepts and implications for dermatology. Journal of the American Academy of Dermatology, 36(6), 895-908.
• Wikner, J., et al. (2015). Graves’ disease and hyperthyroidism: Hair loss and the thyroid. Thyroid Journal, 4(3), 207-214.