Dense multiple dark brown macules; Epidermal hyperpigmentation to bilateral lower extremities; Pfizer, Dose Number: 1, 2, 3, 5 / Moderna, Dose Number: 4; This is a spontaneous report received from contactable reporter(s) (Nurse). The reporter is the patient.  A 48-year-old female patient (not pregnant) received BNT162b2, BNT162b2 omi ba.4-5 (BNT162B2, BNT162B2 OMI BA.4-5), on 14Oct2022 as dose 5 (booster), single (Lot number: GJ3277) at the age of 48 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "Seasonal rhinitis" (unspecified if ongoing); "Hx concussion" (unspecified if ongoing); "Hypothyroid" (unspecified if ongoing); "Migraines" (unspecified if ongoing); "Known allergies: PCN" (unspecified if ongoing); "Known allergies: Vespids" (unspecified if ongoing); "Known allergies: Shrimp" (unspecified if ongoing); "Known allergies: Sulfa" (unspecified if ongoing); details reported as followed: Other medical history included: Seasonal rhinitis, Hx concussion, Hypothyroid, Migraines; Known allergies: PCN, Sulfa, Compazine, Shrimp, Vespids. Concomitant medication(s) included: ZYRTEC [CETIRIZINE HYDROCHLORIDE]; AMANTADINE; SYNTHROID; FLONASE [FLUTICASONE PROPIONATE]; VITAMIN D [COLECALCIFEROL]. Past drug history included: Compazine, reaction(s): "Known allergies: Compazine". Vaccination history included: Bnt162b2 (dose 3, lot number: EW0183, vaccine location: Deltoid), for COVID-19 immunisation; Bnt162b2 (dose 2, lot number: EL3249, vaccine location: Deltoid), for COVID-19 immunisation; Bnt162b2 (dose 1, lot number: EL0140, vaccine location: Deltoid), for COVID-19 immunisation; Moderna covid-19 vaccine (dose 4, lot number: 068H21A, vaccine location: Deltoid), for COVID-19 immunisation. The following information was reported: INTERCHANGE OF VACCINE PRODUCTS (disability) with onset 14Oct2022, outcome "unknown", described as "Pfizer, Dose Number: 1, 2, 3, 5 / Moderna, Dose Number: 4"; MACULE (disability), outcome "recovered with sequelae", described as "Dense multiple dark brown macules"; SKIN HYPERPIGMENTATION (disability), outcome "recovered with sequelae", described as "Epidermal hyperpigmentation to bilateral lower extremities". The events "dense multiple dark brown macules" and "epidermal hyperpigmentation to bilateral lower extremities" required physician office visit. The patient underwent the following laboratory tests and procedures: SARS-CoV-2 test: (18Jul2022) Positive, notes: Nasal Swab. Therapeutic measures were taken as a result of macule, skin hyperpigmentation, treatment reported as Dermatology. Additional information: No other vaccine in four weeks. No covid prior vaccination.; Sender's Comments: Based on available information, a possible contributory role of subject vaccine cannot be excluded for the reported events, based on temporal relationship. There is limited information provided in this report.  This case will be reassessed upon receipt of follow-up information.   The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate