Alopecia areata (overview) L63.8

Celsus, 30-60 AD; Sauvages, 1706

Mostly reversible, sudden onset, asymptomatic, circular hair loss of varying severity and unknown cause (autoimmunological factors are discussed), histomorphologically based on anagen effluvium. Rare are foudroyant courses with complete baldness ("balding overnight").

The severity of alopecia areata can be classified with the SALT score. This is calculated from the extent and degree of hair loss on the scalp and can also be used to monitor therapy.

A distinction is made between:

• Alopecia areata localisata
  • Special form: Alopecia areata of the ophiasistype
• Alopecia areata diffusa
• Alopecia areata totalis
• Alopecia areatauniversalis (maligna)
• Alopecia areata unguium.

Incidence unclear; concerns about 1% of the dermatological patients. The lifetime risk for the occurrence of alopecia areata is 1.7%. The prevalence is given as 0.1-0.2%. There is no clear sex preference.

Discussed:

• Infectious allergic triggering!
• Genetic predisposition (e.g. gene locus TRAF1/C5); in trisomy 21/(Down syndrome, alopecia areata occurs with an above-average frequency of 10% of cases.
• Autoimmunological factors (frequent comorbidity with thyroid diseases, about 20% of patients show an increase in anti-TPO antibodies or anti-TG antibodies).
• AA patients often have lower serum vitamin D levels than control groups. The prevalence of vitamin D deficiency is also increased. Therefore, the authors recommend checking vitamin D levels in patients with circular hair loss.
• Atopic diathesis (familial occurrence in 10-25% of cases, frequent concordant occurrence in identical twins and associations with different HLA markers: DR-4, DR-5, DR-6, DR-7, DR-11, DQ3, DQB-1).
• Psychological factors (possible; scientific evidence lacking).
• Environmental factors (e.g. toxins) are discussed, sustainable evidence is missing
• Immunology: Affected hair follicles lose their "immune privilege" (hair follicles are protected from immune system assault by a lack of MHC and ICAM-1 expression) and, in contrast to healthy hair follicles, express more MHC and ICAM class surface molecules. This allows the presentation of hair follicle antigens. The detection of these autoantigens and the detection of CD4 and CD8 lymphocytes speaks for a T-cell mediated autoimmune pathogenesis. However, CD8 T cells seem to play a central role in the pathogenesis: depletion of CD8 cells leads to hair growth. Here, the Janus kinase (JAK) signaling pathway seems to play an important role. JAK inhibitors (ruxolitinib) have been successfully used in some patients.
• Further molecular findings such as increased expression of cytokines (IL-1 beta, IL-2 and interferon gamma) in lesional scalp still need to be evaluated. The initiators of this event are unknown.

Frequency peaks in the 2nd and 3rd decade of life. According to statistics, only about 6% of patients are older than 60 years. The youngest patient described was 2 months old.

No clear sex preference, although female predominance is noted in some collectives (m:w=3:7).

Familial clustering detectable (about 25-30% of patients; association with trisomy 21 and variations in the TRAF1 gene - Redler S et al. 2010).

In most cases the capillitium is affected (about 70%).

Other sites are:

• eyebrows and eyelashes (1,5%)
• Whiskers (1.5%)
• underarm and pubescent hair
• Rarely extremities or trunk hairs.

Clinical course:

• The clinical picture can be extraordinarily variable. The disease usually begins with a single focus of complete health, so to speak "overnight". Local symptoms are absent.
• Typically, there are circular, centrifugally spreading, possibly confluent, non-inflammatory, rather pale bald patches (no erythema formation in the affected areas).
• In the active marginal area, tufts of hair can be painlessly pulled out as telogenic or dystrophic hairs (see hair cycle below).
• In the active marginal area, pathological stubby hairs are produced (exclamation mark hairs, cadaver hairs - see fig. below).
• Follicles always remain visibly intact (important differentiation from scarring alopecias, in which the follicles are destroyed).
• After weeks to months, hair growth starts again; frequently, regrowing hairs are depigmented. The temporal course of a.a. is mostly chronic, accompanied by relapses and remissions. Relapses can lead to extensive infestation or even universal baldness within a few days.
• A striking observation is that in mottled gray patients, the gray hairs are initially spared. In the case of massive hair loss, this can lead to "greying overnight".

There are 4 degrees of severity:

• Grade 1: Single foci or multiple foci, < 30% of the capillitium.
• Grade 2: Multiple foci > 30% of the capillitium
• Grade 3: Alopecia of the entire capillitium (alopecia areata totalis)
• Grade 4: Alopecia of the entire integument (alopecia areata universalis).

Prognostically unfavourable sign with regard to the progression of the foci: exclamation mark hairs or comma hairs as well as cadaveric hairs in the form of comedone-like "points noirs".

Dense, lymphocytic perifollicular infiltrate with focal follicular infiltration: Only hair follicles of the anagen phase are affected. Pathology: Damage of the follicle by the infiltrate; interruption of the anagen phase; dystrophy of the hair shaft with resulting breakage, incomplete keratinization (exclamation mark hair) or loss. Reduction to a miniature follicle; cyclic renewal of the hair follicle (catagen/telogen) is maintained, while the infiltrate recedes. The new anagen phase leads either to a new infiltrate attack or spontaneous hair growth.

1. Alopecia androgenetica
2. Pseudopélade
3. Alopecia specifica diffusa
4. Microsporias
5. Trichotillomania
6. Lichen planus
7. Lupus erythematosus.
8. Folliculitis decalvans (massive pyodermic folliculitis)

In mild forms, the external therapy options can be exhausted; in rapidly progressive forms, internal therapy can be used directly.

Resistance to therapy: In case of alopecia that cannot be influenced therapeutically, a wig should be prescribed. In extensive cases of alopecia areata this should of course be done at the start of therapy.

Glucocorticoids, topical: Brush single foci 2 times/day, e.g. prednicarbate (Dermatop solution), mometasone furoate (e.g. Ecural solution), triamcinolone acetonide (e.g. Volon A tincture). Treat up to about 1 cm into the healthy-appearing area. Therapy results are unsatisfactory.

Alternative: Intrafocal, strictly intracutaneous injections (use of a dermojet) of triamcinolone crystal suspension (e.g. Volon A 10 diluted 1:3 with LA such as mepivacaine), are therapy of choice for treatment of single foci. Caveat. Injections in the temporal and anterior parietal region, risk of crystals spreading into the retinal arteries with subsequent blindness. Hair regrowth approx. 4-6 weeks after start of treatment. Long-term success is questionable.

Alternative: Calcineurin inhibitors: In studies Pimecrolimus (e.g. Elidel) was applied 2 times/day to the lesional areas. Good results are explicitly described in alopecia areata in the context of the atopic group of forms. Currently, calcineurin antagonists are only approved for the treatment of atopic eczema, so that their use in alopecia areata is off-label. Strictest indication because of unclear long-term side effects!

Alternative: Dithranol: Also described is the production of toxic contact ec zema by dithranol, initially 0.05%, in increasing concentration. Daily applications. Education about dithranol therapy required (see also under psoriasis vulgaris).

Alternative: benzyl nicotinate: hyperemization with 2% benzyl nicotinate or other substances stimulating blood circulation (e.g. head tincture hyperemizing, Rubriment). Application of the essences on the hairless areas. After introduction, the patient can perform this treatment independently, if necessary.

Imiquimod (Aldara 5% cream): Casuistry reports good results (off-label use).

Other:

• External treatments with minoxidil (e.g., Regaine), tretinoin (e.g., Cordes VAS cream, Pigmanorm cream), or ciclosporin A may be tried.
• Barrón-Hernández YL et al. 2017 reported good results for alopecia areata in the eyebrow and eyelid areas using the locally applicable prostaglandin derivative bimatoprost, which has a primary ophthalmologic indication (elevated intraocular pressure). A known "side effect" of this preparation is eyelash growth and increased eyelash pigmentation (see below eyelash lengthening by prostaglandin analogues).
• Thymuskin is reported to have shown a beneficial effect on hair growth in small study cohorts.

PUVA therapy locally ( PUVA bath therapy or PUVA cream therapy). Application of methoxaline is also possible in form of a PUVA-turban. Determination of the MPD to determine the initial UVA dose then slow increase of the UVA dose. Informing the patient about increased light sensitivity in the treated areas.

Recommendation: PUVA therapy 3-4 times/week. If resistance to therapy can be proven after 20-30 treatments: discontinue therapy. Proof of effectiveness from placebo-controlled studies is missing. According to our own experience, successes are verifiable, but unfortunately there is a high recurrence rate and no long-term success!

Glucocorticoids, systemic (numerous publications): In rapidly progressive courses, try methylprednisolone (e.g., Urbason), initially 20-60 mg p.o., reducing below Cushing's threshold after 2-3 weeks. Duration of therapy: 6-8 weeks. Only morbostatic effect is to be expected, regrown hairs fall out again after discontinuation of therapy, only in 20% of cases hairs remain.

Alternative: Glucocorticoid pulse therapy: In a randomized placebo-controlled trial, significant improvements were demonstrated with glucocorticoid pulse therapy (prednisolone 1 time/week 200 mg p.o. for 3 months). Alternative pulse therapy was reported at 5mg/kgKG p.o. every 4 weeks (repeat 9-12x).

Alternative: Dapsone (e.g. dapsone-fatol ): 100 mg/day p.o. for months has also been reported to favorably influence the course in adults. The effect is controversial.

Alternative: Ciclosporin A (e.g. Sandimmun, Optoral): High dose (4-6mg/kgKG/day) gfls. in combination with glucocorticoids (prednisolone 4-5mg/p.o. /day) effective; because of the known side effects of ciclosporin A, the treatment is justifiable only in individual cases. High recurrence rate after discontinuation of therapy.

Alternative: Ciclosporin A - Low dose -application: Low dose application (50-100 mg p.o./day) is currently (with good success -personal experience) in clinical trials.

Alternative: Methotrexate: 10-15mg p.o./week gfls. in combination with glucocorticoids (prednisolone 10-20mg p.o./day).

Alternative: In severe alopecia areata, according to EMA, the oral, selective Janus kinase inhibitor Baricitinib (^Olumiant®) can be used. This has been approved for severe alopecia areata since 01/08/2022 (FDA and EMA). Opportunitic infections have to be considered as side effects.

The JAK inhibitors ruxolitinib (this was successfully used in some patients) and tofacitinib (was used in a dosage of 2x10mg/day/Jabbari et al. 2018; under this therapy there was a regrowth of >50% in about 66% of the affected persons) are to be classified as experimental. Both JAK inhibitors experience significant side effects with prolonged administration. They are not approved for this indication in the EU.

Supportive: Zinc hydrogen aspartate (e.g. Unizink 100®) 2 times/day 50mg p.o. or zinc sulfate (e.g. Solvezink®) 2 times/day 200 mg p.o. for at least 6-8 weeks. In addition, accompanying biotin (vitamin H) e.g. Bio-H-Tin® 1 time/day 1 tbl. p.o. for at least 6-8 weeks, improves hair and nail quality and reduces effluvium. These therapeutic approaches are controversially discussed.

• The prognosis depends on the extent, the number of bald patches, the duration (long clinical course means poor prognosis with regard to healing) as well as on the clinical types (the ophiasis type has a particularly poor prognosis for healing). Other prognostic factors are: first manifestation in childhood before puberty, familial occurrence, associated autoimmune diseases, existence of atopic dermatitis, nail involvement and alopecia areata totalis/ universalis.
• As a rule of thumb, within the first 6 months, 30% of alopecia areata patients show regrowth or complete healing. Within one year it is 50%, after 5 years 75%.
• Spontaneous regrowth usually occurs in the center of the bald spot and spreads to the periphery. Often thin, completely white downy hairs appear first, which are gradually replaced by longer often still unpigmented hairs. Only later does the hair begin to color normally. In older patients, the lesional hairs may remain white for a long time.

Possible forms of treatment of alopecia areata depending on the degree of the disease

The immunotherapy with diphenylcyclopropenone (alternatively: dibutyl squarate), formerly listed as standard therapy for alopecia areata, is obsolete today because of its side effects. It is only listed here for historical reasons:

Diphenylcyclopropenone (DPCP): Immunotherapy with contact allergens for severe, refractory forms of alopecia areata. Currently the most effective treatment modality. Caution. There are no commercial preparations (no drug in the sense of the law), the treating physician bears the full responsibility for the therapy and its NW! Single half-sided application of a 2% DPCP solution to the head to produce contact sensitization: 2-7 days of (desirable) burning and itching, eczema reaction. Next application of a highly diluted DPCP solution (0.001%) 14 days after sensitization, then 1 time/week. Slow increase of concentration. Titration to a dosage (individually very different) that causes an inflammatory reaction with redness and itching the next day and heals with scaling. Treatment 1 time/week initially for 6-12 months, possibly for years. Onset of action after approx. 10 applications. Accompanying therapy with steroid-free creams (e.g. Dermatop base cream etc.). Textile sun protection! In a larger study (142 patients) a "complete response" was observed in about 40% of the cases, a "partial response" in 15%, a "minimal response" in 20% and "no response" in about 30%.

Alternative: Square acid dibutyl ester (SADBE): Alternative to treatment with DPCP, see above.

1. Barrón-Hernández YL et al (2017) Bimatoprost for the treatment of eyelash, eyebrow and scalp alopecia. Expert Opin Investig Drugs 26:515-522.
2. Camacho FM et al (1999) Zinc aspartate, biotin, and clobetasol propionate in the treatment of alopecia areata in childhood. Pediatr Dermatol 16: 336-338
3. Celsus AC (50-60 AD) De medicina. Liber VI, Caput IV, De areis.
4. Haneke E (2013) Diseases of the nails. Dermatologist 64: 519-532
5. Harrison S et al (2003) Optimal management of hair loss (alopecia) in children. Am J Clin Dermatol 4: 757-770.
6. Jabbari A et al (2018) An Open-Label Pilot Study to Evaluate the Efficacy of Tofacitinib in Moderate toSevere Patch-Type Alopecia Areata, Totalis, and Universalis. J Invest Dermatol doi:10.1016/j.jid.2018.01.032.
7. King B et al. (2023) Integrated safety analysis of baricitinib in adults with severe alopecia areata from two randomized clinical trials. Br J Dermatol 188:218-227.
8. Kolde G et al (2007) Successful treatment of alopecia areata with efalizumab. JDDG 9: 834
9. Lutz G (2015) Thyroid disorders in alopecia areata - a critical review. JDDG 13 (Suppl 1) 18
10. Ohlmeier MC et al (2012) Topical immunotherapy with diphenylcyclopropenone of patients with alopecia areata - a large retrospective study on 142 patients with a self-controlled design. JEADV 26: 503-507
11. Safavi KH et al (1989) Incidence of alopecia areata in Olmsted County, Minnessota, 1975 through 1989. Mayo Clin Proc 70: 628-633.
12. Wiseman MC et al (2001) Predictive model for immunotherapy of alopecia areata with diphencyprone. Arch Dermatol 137: 1063-1068
13. Xing L et al (2014) Alopecia areata is driven by cytotoxic T lymphocytes and is reversed by JAK inhibition. Nat Med 20:1043-1049
14. https://www.ema.europa.eu/en/medicines/human/EPAR/olumiant