She states that after receiving VARIVAX, a patient had a reaction which she stated was similar to an arthus reaction that happens with DTaP vaccines.; She reports this looks similar to a contact dermatitis.; She states that the patient's upper arm was very red, a little sore, and very itchy.; She states that the patient's upper arm was very red, a little sore, and very itchy.; She states that the patient's upper arm was very red, a little sore, and very itchy.; She states that the patient's upper arm was very red, a little sore, and very itchy.; On 3/15/2022, he saw an immunologist, who vaccinated him with a second dose of DTaP and observed the patient in-office, where he did immediately develop the same red, painful, itchy reaction.; On 3/15/2022, he saw an immunologist, who vaccinated him with a second dose of DTaP and observed the patient in-office, where he did immediately develop the same red, painful, itchy reaction.; On 3/15/2022, he saw an immunologist, who vaccinated him with a second dose of DTaP and observed the patient in-office, where he did immediately develop the same red, painful, itchy reaction.; On 3/15/2022, he saw an immunologist, who vaccinated him with a second dose of DTaP and observed the patient in-office, where he did immediately develop the same red, painful, itchy reaction.; He then received his first dose of VARIVAX on 11/11/2021 and did not have any adverse effects or symptoms with that VARIVAX vaccination.; This spontaneous report has been received from a physician concerning a male patient of 6-year-old. His concomitant therapies and pertinent medical history were reported as none. On 26-AUG-2020 after receiving his first dose of diphtheria vaccine toxoid (+) pertussis vaccine acellular (+) tetanus vaccine toxoid (DTAP) for prophylaxis. The patient had symptoms of redness, pain, and itching, which similar to an arthus reaction, these events recovered after a week. This was the first time the patient had this type of reaction. The patient had been not vaccinated at all before 2020.  On 11-NOV-2021, the patient was vaccinated with the first dose of varicella virus vaccine live (Oka/Merck) (VARIVAX) (0.5 ml, lot#, expiration date, strength, frequency were not reported) with sterile diluent (manufacturer unknown) (strength, dose, frequency, lot# and expiration date were unknown) subcutaneously in left arm for prophylaxis (reported as "for catching up for kindergarten") (product administered to patient of inappropriate age). The patient did not have any adverse effects or symptoms with this varicella virus vaccine live (Oka/Merck) (VARIVAX) vaccination.  On 15-MAR-2022, the patient saw an immunologist, who vaccinated him with a second dose of diphtheria vaccine toxoid (+) pertussis vaccine acellular (+) tetanus vaccine toxoid (DTAP) (strength, dose, frequency, route, lot number, and expiration date were not reported) for prophylaxis, and observed him in the office, where he did immediately develop the same red, painful, itchy reaction. This looked similar to a contact dermatitis and similar to an arthus reaction (type III immune complex mediated reaction; dermatitis contact). On 22-MAR-2022 (reported as about a week after symptoms started), the patient recovered from the events.  On 29-APR-2022, the patient received his second dose of varicella virus vaccine live (Oka/Merck) (VARIVAX) (0.5 ml, lot# U024765, expiration date: 10-AUG-2023, strength, frequency were not reported) with sterile diluent (manufacturer unknown) (strength, dose, frequency, lot# and expiration date were unknown) subcutaneously in left arm for prophylaxis. Then, the patient's upper arm was very red, a little sore, and very itchy. The area was not hot to the touch, swollen, and the patient did not have a fever. In the most recent reaction, the redness covered about 3 inches by 2 1/2 inches of skin, which was almost his entire deltoid. This looked similar to a contact dermatitis, and similar to an arthus reaction that happens with diphtheria vaccine toxoid (+) pertussis vaccine acellular (+) tetanus vaccine toxoid (DTAP vaccines (type III immune complex mediated reaction; dermatitis contact). When the patient had this reaction, the symptoms persisted for about a week total, but were most severe for the first two days. The outcome of the events were recovered on 06-MAY-2022.  The causality between all the events and diphtheria vaccine toxoid (+) pertussis vaccine acellular (+) tetanus vaccine toxoid (DTAP) was reported as related. The causality between all the events and varicella virus vaccine live (Oka/Merck) (VARIVAX) as well as sterile diluent (manufacturer unknown) was not reported. The evens were not sought medical attention. No lab diagnostics or studies was performed.  Upon internal review, type III immune complex mediated reaction was determined to be medically significant.