To evaluate the efficacy and safety of intralesional injection of vitamin D3 versus intralesional injection of corticosteroids in treatment of alopecia areata.

this will be carried out on 40 patients who attend hair outpatient clinic, department of dermatology, Faculty of medicine, Alexandria University, Egypt.

The patients will be randomly assigned into two groups (A and B), each group contains 20 patients. Patients will be blindly subjected to intralesional injection of triamcinolone acetonide (5mg/ml) using sterile saline for dilution every 4 weeks for 3 sessions (11,12) or intralesional injection of vitamin D (an aqueous preparation of cholecalciferol (Devarol® ampoule 200,000 IU/2 mL, Memphis, Egypt) (2.5 mg/mL) every 4 weeks for 3 sessions. The maximum total amount of vitamin D3 injected into a patient in 1 session will be 5 mg Injection will be preceded by topical anaesthesia under occlusion for 30 minutes.

Inclusion Criteria:

Site: scalp. Extent: localized alopecia areata (less than 50% scalp involvement).

Exclusion Criteria:

1. Other skin diseases affecting the scalp
2. Pregnant or lactating women.
3. Bleeding or coagulation disorders
4. Immunocompromised patients.
5. Known hypersensitivity to vitamin D3.
6. Patients who received systemic or topical treatment for alopecia areata in the last month.
7. Patients taking vitamin D supplements in the last 6 months.
8. Patients treated with topical vitamin D analogues.
9. Patients with diseases known to alter vitamin D level as autoimmune diseases, liver or renal diseases.
10. Obesity (defined as body mass index ≥ 25).