Itching began on scalp in the morning and extended to the rest of the body, turning to dermatographism; Hypersensitivity reaction; This spontaneous case was reported by a consumer and describes the occurrence of MECHANICAL URTICARIA (Itching began on scalp in the morning and extended to the rest of the body, turning to dermatographism) and HYPERSENSITIVITY (Hypersensitivity reaction) in a 21-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 070H21A, 027B21A and 046A21A) for COVID-19 vaccination.     The patient did not had allergy history and general health/medical history.  Concurrent medical conditions included Anxiety. Concomitant products included CITALOPRAM from 01-Apr-2019 to an unknown date for Anxiety.   On 25-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 21-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 22-Dec-2021 at 1:00 PM, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to .25 milliliter. On 04-Jan-2022, the patient experienced MECHANICAL URTICARIA (Itching began on scalp in the morning and extended to the rest of the body, turning to dermatographism) and HYPERSENSITIVITY (Hypersensitivity reaction). The patient was treated with MONTELUKAST (oral) from 18-Jan-2022 to 05-Mar-2022 at a dose of 10 milligram once a day; LEVOCETIRIZINE DIHYDROCHLORIDE (XYZAL) (oral) ongoing from 17-Feb-2022 at a dose of 5 milligram once a day and CETIRIZINE HYDROCHLORIDE (ZYRTEC [CETIRIZINE HYDROCHLORIDE]) (oral) ongoing from 11-Mar-2022 at a dose of 10 milligram once a day. At the time of the report, MECHANICAL URTICARIA (Itching began on scalp in the morning and extended to the rest of the body, turning to dermatographism) and HYPERSENSITIVITY (Hypersensitivity reaction) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 18-Jan-2022, Blood immunoglobulin E (Unknown-less than 0.35): above ref range (less than 0.35  ku/l) (High) Cat epithelium, timothy grass, P. chrysogenum, C. herbarum, A. fumigatus, A. alternata, and mountain cedar were above reference range..         It was reported that, on 04-Jan-2022, 13 days following Moderna booster vaccination, patient developed itching on scalp in the morning and extended to the rest of the body, turning to dermatographism/pressure hives by the end of the day. No changes to items such as shampoos, body wash, lotion, laundry detergents, diet, etc.   On 18-Jan-2022, was prescribed Montelukast. No noticeable change occurred after one month. On 18-Jan-2022 at 14:16 hours, Food and environmental IgE (Immunoglobulin E) panel test was performed, and all values were high as follow s, cat epithelium IgE was 0.60, cat epithelium class was 1, timothy grass IgE was 0.93, timothy grass class was 2, P. chrysogenum IgE was 0.77, P. chrysogenum class was 2, C. hebarum IgE was 1.22, C. herbarum class was 2, A. fumigatus IgE was 2.18, A. fumigatus class was 2, A. alternate IgE was 11.50 and A. alternate class was 3 (Reference range: less than 0.35 KU/L).   On 17-Feb-2022, patient was prescribed Xyzal in addition to the Montelukast. Spontaneous generalized itching was managed by the Xyzal but dermatographism persisted. On 11-Mar-2022, patient visited allergist doctor and skin allergy test for environmental allergies was performed. No previous allergy history. Patient discontinued Montelukast prescription and was recommended to add Zyrtec along with Xyzal. Reporter stated that itching was mostly controlled but dermatographism persisted with some breakthrough itching and hives episodes.