Sex: M
Vaccine: SMALLMNK
Symptoms: Skin lesion, Skin mass, Skin necrosis, Skin ulcer, Varicella virus test negative
Clinical narrative: Monkeypox; Breakthrough infection; Literature citation.  Case reference number US-BN-2025-000359 is a spontaneous literature case report, title as stated above, identified on 18-Mar-2025, and concerns a 28-years-old male patient.  The aim of the article was to cutaneous small vessel vasculitis following anti-rabies vaccine.  The patient's medical history and concomitant medication details were not provided.  On unspecified date, the patient presented to the emergency department with an asymptomatic neck ulcer, worsening from a dermatology clinic visit two weeks prior, as reported the patient's lesion showed rapid progression in ulceration and induration of the patient's neck lesion with superficial erosion when outpatient. The patient reported increased growth and burning and denied tooth pain or abscesses.   On unspecified date, the initial punch biopsy revealed ulceration with focal epidermal and dermal necrosis, nonspecific but suggestive of an infectious process although bacterial, acid-fast bacillus, and fungal cultures were negative. As reported the patient previously saw numerous outpatient providers and received multiple antibiotics without resolution.  On unspecified date, focal skin exam showed a large indurated erythematous mass with central purulent ulceration on the left inferior neck. The patient began broad-spectrum vancomycin and piperacillin-tazobactam (brand name: unknown). Computed tomography showed an early abscess with adjacent cellulitis, reactive lymphadenopathy, and patent vasculature. A second punch biopsy demonstrated nonspecific erosion/chronic inflammation with no organisms identified, negative periodic acid schiff, Grocott Methenamine Silver, fite, and gram stains. The patient later endorsed sensation of the neck lesion "expanding upwards," still without drainage. A third deep punch biopsy was obtained with specimen sent for broad range polymerase chain reaction (PCR) sequencing and next generation sequencing analysis at the University. The patient's blood was sent for microbial cell-free DNA detection to expand infectious workup.   On an unspecified date, five days after presentation, a new lesion was noted on the patient's left lateral wrist, which he reported began as a blister six days prior and evolved into an ulcerated plaque, similar to initial presentation of the neck lesion, and was thus biopsied.  The patient's other laboratory tests included Broad range PCR and next generation sequencing testing returned negative. The deoxy ribonucleic acid (DNA) detection demonstrated 1648 copies of mpox. Dedicated mpox PCR swabs of the neck lesion returned positive. The third neck lesion biopsy showed a superficial and deep dermal/subcutaneous inflammatory infiltrate of lymphocytes, eosinophils, and histiocytes with fibrosis, with intact epidermis and closer magnification revealed a diffuse. Given new DNA and PCR results, retrospective mpox immunostaining was performed, showing focal dot-like positivity at the specimen edge presumably staining follicular epithelium. Wrist biopsy showed an erosion with acute-on-chronic inflammatory dermal infiltrate and positive mpox immunostain with negative Herpes zoster virus 1 (HSV1),  Herpes zoster virus 2 (HSV2), and VZV (Varicella zoster virus) immunostains confirming the diagnosis.  On unspecified date, the patient was diagnosed with monkeypox breakthrough infection.   On unspecified date, the patient stopped treatment with antibiotics and the patient began oral tecovirimat 600 mg twice daily over a five-week period. The patient received a two-injection intralesional cidofovir series over two days as a second agent. The lesion showed improvement one week later. The patient opted to discontinue cidofovir, and the lesion contracted over three months of follow-up.   At the time of initial report, the outcome for the events of monkeypox and breakthrough infection was unknown.  The reporter did not provide seriousness assessment for the events of monkeypox and breakthrough infection, however the events were assessed as serious due to criteria of medical significance. Causality assessment for the same events was not provided.  No further information was provided.; Reporter's Comments: An adult male patient of unspecified age reported as, 50s completed full smallpox vaccination with MVA-BN vaccine for unknown indication. On unspecified date, the patient presented to the emergency department with an asymptomatic neck ulcer. Reportedly, on unspecified date, the patient was diagnosed with the serious event of monkeypox breakthrough infection (medical significance). Monkeypox and breakthrough infection is considered as listed per company convention. The patient's medical history and concomitant medication details were not provided, procedure included renal transplantation, and history drug included cyclosporine, mycophenolate mofetil, low-dose prednisone. The outcome was unknown. Considering that MVA-BN vaccine is a non-replicating vaccine which does not contain the monkeypox, causality for both reported events is assessed as not related to MVA-BN vaccine. As with any other vaccine, vaccination with MVA-BN may not result in protection in all cases. The case is serious due to medical significance.; Sender's Comments: An adult male patient of unspecified age reported as, 50s completed full smallpox vaccination with MVA-BN vaccine for unknown indication. On unspecified date, the patient presented to the emergency department with an asymptomatic neck ulcer. Reportedly, on unspecified date, the patient was diagnosed with the serious event of monkeypox breakthrough infection (medical significance). Monkeypox and breakthrough infection is considered as listed per company convention. The patient's medical history and concomitant medication details were not provided, procedure included renal transplantation, and history drug included cyclosporine, mycophenolate mofetil, low-dose prednisone. The outcome was unknown. Considering that MVA-BN vaccine is a non-replicating vaccine which does not contain the monkeypox, causality for both reported events is assessed as not related to MVA-BN vaccine. As with any other vaccine, vaccination with MVA-BN may not result in protection in all cases. The case is serious due to medical significance.