Evaluate and compare the efficacy and safety of topical cetirizine 1%, versus topical betamethasone valerate 0.1% in the treatment of localized alopecia areata.

Alopecia areata (AA) is one of the commonest autoimmune non-cicatricial hair loss that affects different parts of hair-bearing areas of the body . Nearly 2% of the population at some stage of their life may be affected by alopecia areata while the prevalence of alopecia areata was reported to be between 0.1% to 0.2%. Alopecia areata can occur at any age, although it starts in the first three decades of life in most patients, and both sexes are equally affected. It can present clinically as a well-defined patch of hair loss, diffuse hair loss, reticulate hair loss, ophiasis, ophiasis inversus, alopecia totalis (complete loss of scalp hair), or alopecia universalis (hair loss of all over the body).

Many treatment options including topical, systemic, injectable and laser modalities have been used for the treatment of AA . Among the various treatment options for alopecia areata, topical corticosteroids as betamethasone valerate are considered as standard therapy.

There have been reports on the efficacy/adjunctive role of systemic antihistamines in alopecia areata. Moreover, fexofenadine was found to enhance hair regrowth in two cases of extensive resistant alopecia areata.

Cetirizine hydrochloride belongs to a family of medicines called antihistamines which has varied medical uses and is commonly used to relieve allergy symptoms such as watery eyes, runny nose, sneezing, hives, and itching. In addition, it has been demonstrated that cetirizine inhibits release of prostaglandin D2 and stimulates the release of prostaglandin E2 .

Topical cetirizine was used with good results and with no notable side effects for the treatment of androgenic alopecia. Because of this evidence and the absence of hormonal influence, cetirizine was considered suitable for this kind of hair loss .

Cetirizine is able to increase prostaglandins (PG) E and Fα synthesis, and thus, reduce inflammation. It also decreases prostaglandin D2 (PGD2) synthesis. Prostaglandins E and Fα influence positively hair follicle growth, and stimulate and maintain the anagen phase. So, by increasing the synthesis of prostaglandins E and Fα, cetirizine induces an increase in total and terminal hair density and hair diameter, and a reduction in vellus hair density.

A recent study has shown a significantly increased expression of prostaglandin D2 in the serum and lesional skin of alopecia areata patients than in controls. Also, a case report has demonstrated the improvement of diffuse alopecia caused by palbociclib for the treatment of breast cancer, using topical cetirizine 0.5% solution.

Dermoscopy is a non-invasive diagnostic utility, used to evaluate many skin and hair disorders. It may aid in the diagnosis of many uncertain hair disorders, one of which is alopecia areata. Different dermoscopic characteristics are seen in alopecia areata such as, black dots, yellow dots, tapering hairs (exclamation mark hairs). broken hairs and short vellus hairs.

Inclusion Criteria:

• Participants of both sex with age ≥ 12 years.
• Localized alopecia areata: <50% affection of the scalp surface.
• Stable disease (no new patches or increase in size for at least 2 weeks)

Exclusion Criteria:

• Uncertain diagnosis.
• Age < 12 years.
• Severe forms of alopecia (extensive alopecia; > 50% of scalp surface), ophiasis type, alopecia totalis or alopecia universalis.
• Alopecia Areata outside the scalp.
• Patients who have received topical treatment for alopecia areata in the past month.
• Patients who have received systemic treatment for alopecia areata in the past 2 months.
• Any associated skin or hair disorders.
• Any associated medical condition requiring oral corticosteroids, immunosuppressive or light therapy.
• Presence of any systemic autoimmune disease.
• Pregnant and lactating women
• Unrealistic expectations.

patients with alopecia areata who attend the outpatient clinic of Dematology department ,Assuit University hospital.