The aim of this study is to evaluate the use of fractional carbon dioxide laser versus microneedling in the transepidermal delivery of triamcinolone acetonide and platelet rich plasma in treatment of alopecia areata.

Alopecia areata (AA) is one of the most common forms of non-scarring alopecia involving the scalp and/or body. Estimated incidence of alopecia areata is 20.9 per 100,000 person-years with a cumulative lifetime incidence of 2.1%.

The exact pathophysiology of alopecia areata remains unknown. The most widely accepted hypothesis is that alopecia areata is a T cell-mediated autoimmune condition that is most likely to occur in genetically predisposed individuals.

Although, alopecia areata is a benign condition and most patients are asymptomatic, it can cause emotional and psychosocial distress in affected individuals.

First-line therapies include intralesional corticosteroids, topical corticosteroids, minoxidil, anthralin, topical immunotherapy, prostaglandin analogues, topical retinoids bexarotene, and capsaicin. Second- and third-line treatments include topical and systemic immunomodulatory therapies such as oral and topical psoralen plus UVA radiation and photodynamic therapy.No treatment is either curative or preventive. Since no single treatment option is certain to treat alopecia areata, the need for new therapies is mounting.

Intralesional corticosteroids, most commonly triamcinolone acetonide are considered a first-line treatment method for limited disease and can be used as adjunctive therapy in extensive disease. Because triamcinolone is only emulsified temporally to the water, usually it is delivered by the painful intralesional injection.

Platelet-rich plasma (PRP) has emerged as a new treatment modality in dermatology, and preliminary evidence has suggested that it might have a beneficial role in hair growth.

Drugs applied topically have the advantage of fewer side effects, and bypassing the first-pass effect. However, transepidermal dermal drug delivery has limitations, including decreased penetration of larger and water-soluble molecules.

Several strategies have been used to improve many drug penetrations into the skin: microneedling, ultrasound, and more recently transepidermal drug delivery (TED). TED is a technique based on applying a medication following an ablative method (CO2 laser, erbium lasers or ablative radiofrequency), which create vertical channels to assist the delivery of topically applied drugs into the skin. The use of nonablative lasers as well as microneedling technique has been reported with the same purpose.

Fractional laser-assisted drug delivery of corticosteroids for resistant alopecia areata is a new concept in dermatological therapy.

Microneedle devices, such as Dermaroller and Dermapen, are minimally invasive devices that bypass the stratum corneum barrier, thus accessing the skin microcirculation and achieving systemic delivery by the transepidermal route.

Trichoscopy, hair and scalp dermoscopy, is a fast, non-invasive method useful in the diagnosis and therapeutic monitoring of scalp and hair diseases.

Inclusion Criteria:

1. Patients with alopecia areata of either gender, diagnosed both clinically and by trichoscopy
2. Patients not responding to treatment (topical and/or systemic), used properly and regularly, for at least 3 months duration

Exclusion Criteria:

1. Alopecia areata with evidence of spontaneous hair regrowth
2. Patients having active scalp inflammation or other scalp or hair diseases
3. Pregnant and lactating women
4. Patients with any bleeding disorder or receiving anti-coagulant therapy
5. Immunocompromised patients