What Causes LPP? Stress, Hormones, or Autoimmunity?

Lichen planopilaris (LPP) is an immune-mediated condition where the immune system mistakenly targets the body’s own hair follicles. The exact, initial cause of LPP is unknown, but one thing is certain: you did not cause this. It is not the result of poor hygiene, infrequent hair washing, or any personal failing ^[1][2]. It is also not contagious. Current research points to several possible susceptibility factors—such as genetics and immune system changes—but for most people, no single cause can be identified.

Because LPP can cause permanent scarring, unexplained progressive hair loss with scalp redness, scale, itching, pain, or loss of visible hair follicle openings warrants timely evaluation by a dermatologist. Treatment focuses on stopping or slowing active inflammation to protect follicles that are still healthy; unfortunately, hair from a follicle that is already scarred and destroyed cannot regrow ^[3].

How LPP Affects the Hair Follicles

Under normal circumstances, hair follicles have immune privilege, meaning they are protected from the body’s immune system. In LPP, the current scientific model suggests this protection may break down ^[3]. Certain immune cells (specifically T cells and macrophages) accumulate around the upper part of the hair follicle ^[4][5].

Researchers believe these cells may damage the “bulge” region, which is where crucial hair stem cells live. When these stem cells are injured by inflammation, the follicle loses its ability to regenerate hair and is eventually replaced by scar tissue ^[3][4]. While we understand this likely sequence of events, researchers still do not know why immune privilege is lost in an individual patient.

Are Autoimmune Conditions to Blame?

Because LPP involves the immune system, it shares characteristics with autoimmune diseases. People with LPP are reported to have higher associations with other immune-mediated conditions in some observational studies. These can include:

• Thyroid disorders (like hypothyroidism) ^[6]
• Systemic lupus erythematosus (SLE) ^[7][8]
• Psoriasis and vitiligo ^[6][8]
• Rheumatoid arthritis ^[6]

However, having one of these conditions does not cause LPP, and most people with LPP do not necessarily have a systemic autoimmune disease ^[6]. Their occasional overlap just suggests that some individuals have a general susceptibility to immune system misdirection. Universal screening for all of these diseases is not automatically indicated for everyone with LPP. Instead, your dermatologist may recommend specific tests (like thyroid checks) guided by your personal symptoms, physical exam, and family history ^[6].

The Role of Stress and Hormones

Many patients wonder if a highly stressful period or hormonal changes triggered their LPP.

• Stress: Questionnaire-based studies show an association between LPP and a history of major stressful life events ^[9]. However, this does not prove that stress causes the condition. Scarring hair loss causes significant psychological distress, making it hard to tell whether stress preceded the disease or resulted from it ^[10]. Stress management and counseling can support your emotional wellbeing, but they are not a treatment for the immune process itself.
• Hormones: Some studies have noted an association between LPP and postmenopausal status in women ^[9]. A related but distinct scarring hair loss condition called frontal fibrosing alopecia (FFA) has shown mixed associations with pregnancy history and hormone replacement therapy ^[11][12]. However, these observational associations do not establish that hormonal changes or androgen levels cause classic LPP, which can occur at any age and outside the postmenopausal group. Do not stop or change any prescribed hormone therapy without discussing it with your clinician.

Genetics, Medications, and the Environment

Researchers have explored other potential contributors, but the evidence is limited or weak:

• Genetics: Genetic susceptibility may contribute, but LPP is not a predictably inherited disease, and there is no routine genetic test for it. While specific genetic markers have been noted in small studies ^[13], familial cases of LPP are rare or incompletely characterized ^[14]. Having a relative with common, non-scarring hair loss (like male or female pattern baldness) does not by itself establish a meaningful risk for LPP.
• Medications: In rare, isolated case reports, certain medications (like specific biologics) have been linked to LPP-like hair loss ^[15][16]. Never stop taking a prescribed medication without speaking to your doctor first, as untreated underlying conditions can be dangerous, and drug-induced LPP is very uncommon.
• Environmental Factors: Some questionnaire studies report very weak associations between LPP and the use of hair dyes or facial soaps ^[9]. There are also isolated reports of LPP appearing after scalp trauma (like a hair transplant) ^[17] or exposure to certain occupational chemicals ^[18]. These are not proven causes. Ordinary cosmetics and daily hygiene are not established causes of LPP; avoiding a product is mainly reasonable if it actively irritates your scalp.
• Infections: Studies of the scalp microbiome (bacteria and viruses) are ongoing, but researchers have not found a proven viral or bacterial infection that initiates classic LPP ^[19][2].

Ultimately, LPP is not something you caused. For most people, no specific cause can be identified; current research points to several possible susceptibility factors and immune mechanisms. Focusing on what you can do—partnering with your dermatologist to monitor and control active inflammation, practicing gentle scalp care, and seeking emotional support—is the most empowering path forward.