**5. Treatment protocol**

Despite the absence of a universally proven protocol that sustains prolonged remission, many therapeutic regimens for using excimer are available, which can benefit both children and adults with AA. Although the two types (laser and lamp) have similar effects, the difference between them is their technology. An excimer lamp is less expensive than an excimer laser, and it has a more prominent spot size that delivers a high dose of UV radiation to the selected treatment area. Wide spot size helps in treating a larger area in a short time. Any treatment options are frequently based on several parameters, including:


*Overview of the Role of 308 Monochromatic Excimer Phototherapy for the Treatment of Alopecia… DOI: http://dx.doi.org/10.5772/intechopen.108531*


Before starting the treatment with monochromatic excimer light, you must calculate the minimal erythematous dose on healthy, unexposed skin. The volar aspect of the forearm is commonly used to determine the starting dose (usually 0.5–0.7 MED).


In evaluating AA treatments, clinicians require valid, clinically meaningful outcome measures.

In 2004, the SALT (Severity of Alopecia Tool) score emerged as a key milestone in the AA field, providing a standardized method to derive 0–100% of the scalp-hair loss. Building on this achievement, the AA-IGA (Alopecia Areata Investigator Global Assessment) provides an ordinal, static measure with five distinct clinical gradations of SALT score ("None" = 0, "Limited" = 1, "Moderate" = 2, "Severe" = 3, and "Complete" = 4). AA-IGA is a meaningful clinician-reported measure of scalp-hair loss, reflecting patients' and expert clinicians' perspectives and treatment expectations [35]. Assessment of hair regrowth is based on the change in the SALT score or AA-IGA.

The percentage of hair that grew back after laser treatment was assessed using a six-grade scale. The first grade was A0, where no change was detected in the number of hair (poor). The second grade was A1, with 1–25% regrowth (mild), and the third grade was A2, which was equal to 25–49% (moderate). The fourth grade was A3, with 50–74% regrowth (good), and the fifth was grade A4, with 75–99% regrowth (very good). The sixth grade was A5, with 100% regrowth (excellent).

Absolute change in SALT score = SALT score at baseline − SALT score after treatment. Percent scalp hair regrowth is based on SALT score = (100 × [baseline SALT score − SALT score after treatment])/baseline SALT score.

The results indicated that hair growth in more than 50% of the area was regarded as a successful response, while that with less than 50% range was considered to be an inadequate response. The poor response was evaluated when the SALT equaled zero. The overall response rate was the percentage of patients who responded positively to the treatment [17].

Evaluation is carried out at four points (baseline, 4 weeks, 8 weeks, and 12 weeks). The SALT score was recorded from the baseline to the last visit and digital photographs were taken at the same points.

The efficacy of the equipment was evaluated by the objective recording of adverse reactions and patient satisfaction. Follow-up continued for 6 months to 1 year after treatment to assess the level of recurrence. Excimer can be used as a monotherapy or combined with another treatment. The additive treatment can be topical, such as corticosteroid or calcineurin inhibitors, and it can be in the form of systemic therapy, such as methylprednisolone or triamcinolone acetonide.
