Scarring Alopecia and Peripilar Casts: What I'm Looking For During Consultations
08 / 24 / 23

Scarring Alopecia and Peripilar Casts: What I'm Looking For During Consultations

Like other hair restoration physicians, many women come to see me because of recent hair loss. During the consultation, I aim to diagnose their type of alopecia/hair loss because different types of alopecia have different underlying causes and may need different approaches to treatment. After analyzing their medical and hair loss history, if hair loss is the only symptom, this can indicate genetic alopecia (easier to treat). However, some women have additional symptoms like scalp tenderness, itching, or burning. Also, when questioned, some have lost other body hair, including eyebrows and eyelashes. (These additional symptoms are not the case for everyone.)
I need an accurate diagnosis and know what I am treating (which I often confirm through a biopsy) to recommend treatment plans most effective for my patient's needs.

When the history of hair loss is inconsistent with androgenetic alopecia and the physical exam is not definitive, I look specifically for evidence of something called peripilar casts using a magnifying lens. Peripilar casts are small, white, thread-like structures that form around the hair shaft and can be seen emerging from hair follicles in some cases of alopecia. The casts themselves are made up of keratin, which is the same protein that makes up hair and nails.

Why Do I Look For Peripilar Casts?

Peripilar casts can be associated with a scarring alopecia diagnosis. Scarring alopecia, also known as cicatricial alopecia, is a type of hair loss that results from the destruction of hair follicles and subsequent replacement with scar tissue. Peripilar casts can sometimes be seen in the early stages of scarring alopecia, particularly in conditions like lichen planopilaris and frontal fibrosing alopecia. These conditions cause inflammation and destruction of the hair follicles, leading to the formation of peripilar casts around the affected hair shafts.

It is important to note that the presence of peripilar casts alone does not mean the patient has scarring alopecia.

Here are some other causes of peripilar casts:

  1. Fungal infections like tinea capitis. Infections are usually characterized by circular patches of hair loss, itching, and scaling on the scalp.
  2. Seborrheic dermatitis is a common skin condition that causes red, scaly patches on the scalp, along with itching and flaking. In some cases, it can lead to the formation of peripilar casts.
  3. Pityriasis amiantacea is a condition characterized by thick, scaly plaques on the scalp that tightly adhere to the hair shaft. These plaques can trap dead skin cells and sebum, leading to the formation of peripilar casts.
  4. Psoriasis is a chronic autoimmune condition that affects the skin, including the scalp. It causes red, scaly patches that can lead to the formation of peripilar casts.
  5. Folliculitis is the inflammation of hair follicles, usually caused by bacterial or fungal infections. It can lead to the formation of peripilar casts and symptoms like redness, swelling, and pustules on the scalp.
  6. Certain hair care products, such as shampoos, conditioners, or styling products, may contain ingredients that can cause a buildup of residue around the hair shaft, forming peripilar casts.
  7. Head lice can lay eggs, known as nits, on the hair shaft close to the scalp. These nits can resemble peripilar casts and may be visible on the scalp.

Further evaluation through a scalp biopsy is required for a diagnosis. Even though there are other potential causes of peripilar casts to consider, none of these have the same hair loss implications as scarring alopecia, so I always want to ensure we have an accurate diagnosis through a biopsy, if possible.

Cast Presentations

I also wanted to show various cast presentation examples from my patients to illustrate why in-person consultations are essential because hair loss might appear as average genetic hair loss. These patients came in for a consultation experiencing symptoms more than hair loss. Upon further evaluation of their hair follicles, peripilar casts were present. I did a biopsy, and all diagnoses proved to be a scarring alopecia of either Lichen Planopilaris (LPP) or Frontal fibrosing alopecia (FFA). Both types of hair loss require different layers of treatments with varying strengths of anti-inflammatories.

This patient was diagnosed with Frontal fibrosing alopecia (FFA), a variant of lichen planopilaris, which affects the frontal scalp and eyebrows. Bald patches and scarring appear at the hairline near the forehead.

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Casts present:

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These patients were diagnosed with Lichen planopilaris, which presents as hair thinning. Bald patches may accompany it, masquerading as genetic hair loss. Patients may also have scalp pain, itching, or burning.

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Casts Present:

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Casts present:

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More examples of casts on other LPP patients:

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If you are experiencing hair loss or other symptoms related to your scalp or hair, it is important to schedule a consultation appointment. While hair loss can be a natural part of aging, it can also be a sign of an underlying medical condition. A consultation appointment will allow me to assess your symptoms and determine the best course of action for treatment. Don't wait to seek help if you are experiencing hair loss or other symptoms - early detection and treatment can make a big difference in the outcome.