Types of hair loss: Alopecia areata
Types of hair loss: Alopecia areata

WHAT IS ALOPECIA AREATA

Alopecia areata is a type of hair loss that is also known as ‘spot baldness’.  This type of hair loss often appears as a number of bald spots in the scalp, though hair loss can affect any area of the body.  Alopecia areata often appears in women that are otherwise healthy.  In a few cases, all the hair on the scalp is lost (alopecia totalis) or over the whole body (alopecia universalis).  Onset and remission is generally unpredictable and in rare cases the hair loss is permanent.

Alopecia areata is thought to be an autoimmune condition stemming from collapse in immune competence.  Whilst there is no absolute known cure for the condition, there are a number of treatments that can reduce onset and lower severity of the condition.

CLINICAL FEATURES OF ALOPECIA AREATA

Women normally notice small bald patches where the hairless patches appear superficially normal and unscarred.  Whilst the patches can take on many different shapes, they normally appear round or oval.  There can be areas that are regrowing and other active areas of hair loss at the same time.

Some patients notice tingling or mild pain in the areas where hair loss is active.  Hairs that have an “exclamation point” appearance are also characteristic of the disease.  These hairs are normally surrounding the bald patches, thinner near the scalp and only 3-5mm in length.  These exclamation hairs are pulled out more easily than unaffected hairs.

CAUSES OF ALOPECIA AREATA

Alopecia areata is considered to be an immune mediated disorder stemming from the body mistakenly attacking it’s own cells.  Scalp biopsies carried out to diagnose the cause of hair loss often show a large number of T-cells around the base of the follicle. These T-cells cause inflammation that eventually arrests cell growth and leads to the arrest of hair growth.

A number of studies have shown an imbalance in T-cell populations with a marked decrease in regulatory T-cells [2-4].  Regulatory T-cells regulate the immune response and prevent the immune response from overreacting to any perceived threats.  A study in 2019 by the National Alopecia Areata Foundation identified a number of regulatory T-cells are preferentially located to hair follicles. They were required for proper hair cycling and hair growth, they looked at novel therapies to enhance regulatory T-cell populations.

For hair to grow normally, the hair must retain its immune privilege and be safe form the actions of the innate or adaptive immune system. There are a number of contributing factors that determine whether some is likely to suffer form alopecia areata including: genetics, environmental factors and prior infections.

In some cases, alopecia is the only known sign of celiac disease [1].  One study found that a number of patients experienced complete remission of the disease after following a gluten free diet.  The study looked at how celiac disses was associated with a number of allergies, inflammatory conditions and other miscellaneous diseases.

Alopecia areata and T-cells

T-cell populations – There is a marked difference in T-cell populations in patients with alopecia areata.

CAN ALOPECIA AREATA BE TREATED SUCCESSFULLY?

There are a number of promising therapies for alopecia areata.  Success often depends on the individual and the severity of the disease.

Potential therapies for alopecia great include:

Corticosteroid therapy – Steroid injections have been used to manipulate the inflammatory actions in the scalp for over 50 years.  Studies showed that 71% of patients showed hair regrowth with 3 treatments carried out fortnightly [5] and another study showed 63% of patients experienced hair regrowth after 4 months after receiving monthly injections [6].  The process involves injecting corticosteroids into the hairless regions of the scalp and are usually given by a dermatologist.  This type of treatment is more suited to those who have less than 50% of the scalp affected.

JAK inhibitors – JAK inhibitors such as are often used in inflammatory diseases and another of autoimmune diseases.  They work by modifying the immune response and cell messenger activity.  JAK inhibitors and tyrosine supplementation have been shown to help restore lost hair in alopecia patients.

Nutritional therapy – Zinc supplementation has been shown to be effective in the treatment of alopecia.  A number of studies have shown that increasing serum zinc results in hair regrowth in all cases.  Zinc and alopecia areata are connected in that zinc modifies the immune response and thus lessens the aggression of T-cells and the inflammatory response around the hair follicle.  Other studies link soybean oil to alopecia recovery.

Other medications – Prescription medication has shown some success in the treatment of alopecia areata.  Diphencyprone and anthralin has shown modest success in severe cases.

THE FINAL WORD

If you believe you are suffering from alopecia areata, it is important to seek advice.  Alopecia areata can occur by itself or with other autoimmune or inflammatory diseases.  Most patients experience spontaneous relapse; in other words, the condition often goes away by itself.  Whilst the condition may not go away permanently, treatment can often reduce the severity of the condition.

REFERENCES

  1. Caproni, M., Bonciolini, V., D’Errico, A., Antiga, E. and Fabbri, P., 2012. Celiac disease and dermatologic manifestations: many skin clue to unfold gluten-sensitive enteropathy. Gastroenterology Research and Practice, 2012.
  2. Speiser, J.J., Mondo, D., Mehta, V., Marcial, S.A., Kini, A. and Hutchens, K.A., 2019. Regulatory T‐cells in alopecia areata. Journal of cutaneous pathology, 46(9), pp.653-658.
  3. Todes-Taylor, N., Turner, R., Wood, G.S., Stratte, P.T. and Morhenn, V.B., 1984. T cell subpopulaions in alopecia areata. Journal of the American Academy of Dermatology, 11(2), pp.216-223.
  4. Strazzulla, L.C., Wang, E.H.C., Avila, L., Sicco, K.L., Brinster, N., Christiano, A.M. and Shapiro, J., 2018. Alopecia areata: disease characteristics, clinical evaluation, and new perspectives on pathogenesis. Journal of the American Academy of Dermatology, 78(1), pp.1-12.
  5. Abell E, Munro DD. Intralesional treatment of alopecia areata with triamcinolone acetonide by jet injector. Br J Dermatol 1973: 88: 55–59.
  6. Kubeyinje EP. Intralesional triamcinolone acetonide in alopecia areata amongst 62 Saudi Arabs. East Afr Med J 1994: 71: 674–675

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