Introduction

Alopecia areata is an autoimmune disorder, which implies your body’s resistant framework botches your solid tissues as perilous and starts assaulting them. Alopecia areata is a common skin illness. The word alopecia implies bare; areata implies inconsistent. The infection causes hair misfortune on the scalp, confront, and in some cases other body zones, like beneath the arms or on the legs. Individuals with alopecia areata most regularly lose hair in circular, coin-sized patches on the scalp, but in more extreme cases, they may lose all of their hair. Almost 2% of individuals all over the world will suffer from alopecia areata at a few points in their lifetime.¹

There are three fundamental sorts of alopecia areata:

• Patchy alopecia areata- In this sort, which is the most common, hair misfortune happens in one or more coin-sized patches on the scalp or other parts of the body
• Alopecia totalis- Individuals with this sort lose all or about all of the hair on their scalp
• Alopecia universalis- In this sort, which is uncommon, there is a total or about total misfortune of hair on the scalp, face, and rest of the body

Aetiology

Alopecia areata is an immune system malady that causes your safe framework to assault your body. Your resistant framework assaults your hair follicles since it considers they’re remote intruders - microbes, infections, parasites or organisms - that cause disease, sickness and disease.

When this happens, your hair starts to drop out, and regularly clumps the measure and shape of a quarter. The degree of the hair misfortune shifts. In a few cases, it’s as it were in a few spots. In others, the hair misfortune may be more noteworthy, counting adds up to hair loss.

Your hereditary cosmetics (the parts of your cells that decide your physical characteristics, like eye colour, tallness or hair colour) may trigger your body’s immune system response. Or your hereditary cosmetics combined with an infection or another substance you experience may trigger the response.

Symptoms

Common symptoms of alopecia areata include:

• Patches of hair loss, including your scalp, facial hair, eyebrows, eyelashes and body hair
• Nail pitting

Your patches won’t typically have any other symptoms, but in rare cases, they may:

• Itch (pruritus)
• Change colour (red, purple, brown or grey)
• Develop visible, mouth-like openings in your hair follicles (follicular ostia)
• Have black dots, which are hair shafts that are visible in the follicular ostia (cadaver hairs)
• Grow short hairs that are thicker on the top and narrow toward your scalp (exclamation point hairs)
• Grow white hairs²

Immunotherapy overview

Immunotherapy for alopecia areata (AA) is a treatment that involves applying a chemical to the skin to induce an allergic reaction that stops the immune system from attacking hair follicles. This treatment is also known as topical immunotherapy or contact immunotherapy.³

Types Of Immunotherapy

1. Topical Immunotherapy: 

Topical immunotherapy is characterized as the acceptance and intermittent elicitation of unfavourably susceptible contact dermatitis (ACD) by applying a strong contact allergen. In 1965, the alkylating operator triethyleneimino benzoquinone was, to begin with, a topical sensitizer utilized to treat cutaneous malady, but it was deserted on account of its mutagenicity. Afterwards, nitrogen mustard, harm ivy, nickel, formalin, and primin were attempted, basically as topical immunotherapy, for Alopecia Areata and warts. Contact immunotherapy was presented in 1976, by Rosenberg and Drake. Afterwards, strong contact allergens specifically dinitrochlorobenzene (DNCB), squaric acid dibutylester (SADBE), and diphencyprone (DPCP) superseded the prior utilized allergens.³

2. Systemic Immunotherapy:

Systemic immunotherapy involves treatments that suppress or modulate the immune system to prevent it from attacking hair follicles. Common approaches include oral corticosteroids to reduce inflammation, JAK inhibitors (like tofacitinib) that block immune signalling pathways, and immunosuppressants such as methotrexate and cyclosporine. These therapies are typically used for severe cases, as they carry risks like infections, organ damage, and relapse after discontinuation. JAK inhibitors have shown promising results in promoting hair regrowth, though long-term use and side effects remain concerns.³

Common Immunotherapy Agents

• Diphencyprone(DPCP): 

Diphenylcyclopropenone (diphencyprone) is a topically managed exploratory medication expected for treating alopecia areata and alopecia totalis. Diphenylcyclopropenone triggers a resistant reaction that is thought to contradict the activity of the autoreactive cells that something else causes hair misfortune. One theory is that in reaction to DPCP treatment, the body will endeavour to downregulate aggravation through an assortment of pathways, coming about in a downregulation of the immune system reaction at the hair follicle. This autoinflammatory response would devastate the body's hair follicles. Think about its 40-80% viability in regrowth.

• Squaric Acid Dibutyl Ester (SADBE): 

Squaric acid dibutyl ester (SADBE) as topical immunotherapy is a great elective in patients with hard-headed alopecia areata. It works by diverting the incendiary reaction and causing an unfavourably susceptible contact dermatitis to trigger hair regrowth. The advancement rate in all alopecia patients treated with SADBE topical immunotherapy was 57.8%.

•  Anthralin:

Anthralin is also known as Dithranol, a topical medicine utilized to treat psoriasis, alopecia and other skin conditions. Anthralin's chemical structure permits it to be ingested well through the epidermis. It's also known to have anti-inflammatory properties. It is regularly utilized in combination with other medicines.

• JAK Inhibitors (Tofacitinib, Ruxolitinib): 

JAK inhibitors are immune-modulating drugs that block the activity of JAK(Janus kinase) enzymes, which are responsible for turning on the immune system. This helps to reduce inflammation. JAK inhibitors regulate the activity of cytokines that are involved in AA, such as interleukin-15 and interferon-gamma. This can lead to hair regrowth. Some JAK inhibitors include baricitinib, ritlecitinib, tofacitinib, and ruxolitinib.    

Treatment Protocol

Topical Application:  

• Induction phase: In the induction phase of alopecia areata treatment, high-potency topical corticosteroids are applied daily for 4-6 weeks to reduce inflammation. For extensive cases, low concentrations of topical immunotherapy agents like DPCP or SADBE are initially applied to test sensitivity, followed by weekly applications to induce immune diversion. Topical minoxidil (5%) may be used twice daily to promote hair growth, and anthralin can be applied as a short-contract irritant. Regular follow-ups are necessary to monitor response and adjust treatment as needed
• Maintenance phase: In the maintenance phase of treatment, the focus is on sustaining hair regrowth and preventing relapse through a combination of strategies. Low-potency topical corticosteroids (fluocinolone or hydrocortisone) are applied once daily or several times a week to minimize inflammation. Topical immunotherapy agents like DPCP or SADBE are continued at reduced concentrations every 4-6 weeks to maintain immune modulation. Patients should also apply topical minoxidil(5%)twice daily to support ongoing hair regrowth. Regular follow-up appointments every 8-12 weeks are essential to assess progress, manage side effects, and adjust treatment as needed, alongside incorporating stress management techniques and a balanced diet for overall hair health

Systemic Treatment:

• Systemic treatments for alopecia areata, used in severe cases require careful dosing and monitoring. Oral corticosteroids like prednisone are typically dosed at 0.5-1 mg/kg per day, tapered over 6-12 weeks, with regular monitoring for side effects. Methotrexate is dosed at 10-25 mg weekly, often combined with corticosteroids, and requires baseline and regular monitoring of liver function, renal function, and blood counts. For newer treatments like tofacitinib (a JAK inhibitor), the usual dose is 5 mg twice daily, with monitoring for infections, lipid levels, and liver enzymes to manage potential side effects. Regular follow-ups are crucial to adjust doses and ensure treatment safety

Side Effects and Risks:

Topical Immunotherapy:

• Skin reactions: Itching, rashes, erythema, burning, papules, vesicles, and bullae 
• Hyperpigmentation: Irreversible hyperpigmentation of the head and neck area 
• Other side effects: Sleep disturbances, fever, general malaise, lymph node enlargement, and flu-like symptoms
• Other potential side effects include: occipital lymphadenopathy and vitiligo macules⁴

Systemic Immunotherapy:

• Mild to moderate eczema: A common adverse reaction to DPCP topical immunotherapy
• Severe eczema: A frequent adverse effect of contact immunotherapy, including blistering, scaling, or exudation
• Lymphadenopathy: A common adverse effect of contact immunotherapy
• Hyperpigmentation: A common adverse effect of contact immunotherapy
• Hypopigmentation: A common adverse effect of contact immunotherapy
• Influenza-like symptoms: A common adverse effect of contact immunotherapy
• Erythema multiforme major: A rare but serious side effect of DPCP
• Discoid lupus erythematosus: A rare but serious side effect of DPCP

Other side effects of alopecia areata treatments include:

Headache, Scalp irritation, Unusual hair growth, Scalp atrophy, Cataracts, and Glaucoma.⁴

Combining Immunotherapy with Other Treatments

Corticosteroids

• Intralesional corticosteroids: For restricted scalp alopecia areata, intralesional corticosteroid treatment is considered the medication of choice by numerous specialists. The most broadly utilized operator is triamcinolone acetonide
• Topical corticosteroids: Numerous types of topical corticosteroids have been endorsed for alopecia areata, counting creams, gels, treatments, salves, and froths. Sixty-one percent of patients utilizing 0.1% betamethasone valerate froth accomplished more than 75% hair regrowth in comparison with 27% in the 0.05% betamethasone dipropionate salve gather. Topical corticosteroids are distant and less compelling in alopecia totalis and alopecia universalis⁵

Minoxidil

• In a placebo-controlled, double-blind ponder, hair regrowth was watched in 63.6% and 35.7% of the minoxidil-treated and fake treatment bunches, separately. Be that as it may, as it were, 27% of the minoxidil-treated patients appeared cosmetically worthy of hair regrowth. In another consideration, hair regrowth was accomplished in 38% and 81% of patients treated with 1% and 5% topical minoxidil, respectively. Most ponders have appeared no useful impact of topical minoxidil in alopecia totalis and alopecia universalis. Minoxidil 5% arrangement or froth is habitually utilized with other helpful specialists as an adjuvant treatment. The antagonistic impacts of topical minoxidil incorporate contact dermatitis and facial hypertrichosis⁵

Phototherapy

• Phototherapy uses ultraviolet light from special lamps. Your healthcare provider may use a drug called psoralen combined with ultraviolet A (PUVA) or ultraviolet B (PUVB). The ultraviolet light waves in phototherapy can help certain skin and nail disorders, including alopecia areata²

Future Directions

Future directions of immunotherapy in alopecia areata are focused on enhancing targeted treatment approaches and understanding the underlying mechanisms of the disease. Research is exploring the use of biologics, such as JAK inhibitors, to more effectively modulate the immune response and promote hair regrowth. Additionally, personalized medicine strategies that consider genetic and environmental factors may lead to more effective therapies. Combining immunotherapy with other modalities, like topical treatments or lifestyle interventions, is also being investigated to improve outcomes. Overall, advancements in immunotherapy aim to provide more durable and effective solutions for individuals suffering from alopecia areata.

Conclusion

In conclusion, immunotherapy speaks to an imperative and advancing approach to treating alopecia areata, tending to the immune system nature of the condition by balancing the resistant reaction to reestablish hair development. With medicines such as corticosteroids and JAK inhibitors appearing promising, progressing inquiries about proceed to investigate more focused on and personalized procedures. As our understanding of the illness extends, the potential for immunotherapy to give successful and enduring arrangements for people influenced by alopecia areata offers trust for the progressed quality of life and a brighter future in hair misfortune administration.