Herpes zoster ophthalmicus (HZO); Literature citation: Information has been received from the authors in a published literature article title as stated above, concerning a previously healthy 14-month-old male wit no history of significant rashes or serious infections. Newborn screening was negative for severe combined immunodeficiency or T cell lymphopenia. He had no close contacts with shingles or chicken pox, and no known exposure to varicella in utero or after birth. The patient was up to date on age-appropriate vaccinations and the varicella vaccine (manufacturer unknown) (strength, dose, route of administration, lot number and expiration date weer not reported) was administered on an unknown date for prophylaxis to the right thigh 11 weeks before presentation. His mother had chicken pox as a child. His father, paternal uncles and paternal grandmother have selective IgA deficiency.  On an unknown date, the patient presented to his pediatrician with a 3-day history of a painful unilateral rash involving the right ophthalmic (V1) dermatome, consisting of eroded papules with yellow adherent crust on the upper eyelid, forehead and frontal scalp. There were no intact vesicles or pustules, and Hutchinson's sign was negative. All vital signs were normal. Associated symptoms included irritability, difficulty sleeping and decreased oral intake. He had no associated fever, chills, neurologic deficits, upper respiratory symptoms, nausea, vomiting or diarrhea. Ophthalmology examination confirmed external HZ ocular involvement with surface disease including punctate erosions of the conjunctiva and cornea. Immediately after evaluation by ophthalmology, dermatology obtained surface swabs for herpes simplex virus (HSV) and VZV. Although HSV infection was in the differential, the clear dermatomal demarcation made VZV the most likely etiology. He was directly admitted to the hospital for intravenous antiviral treatment.   Laboratory Investigation HSV PCR was negative. VZV PCR was positive, and the Laboratory of Hygiene confirmed a positive test for the vaccine-strain. Extensive immune testing was performed during acute illness and after recovery (1424 months of age). Complete Blood Count (CBC) with differential was normal, and HIV testing was negative. Flow cytometry showed normal numbers of T cells, B cells and natural killer cells. T cell proliferation response was normal with mitogen, T cell receptor crosslinking and VZV stimulation. Natural killer cell cytotoxic activity was normal. Initially, total serum IgG was low at 302 mg/dL (ref: 4751210 mg/dL) with both IgA (ref: 21291 mg/dL) and IgM (ref: 41183 mg/dL) in the normal range. Repeat testing at 18 months demonstrated a persistently low IgG level at 321 mg/dL, a slightly decreased IgM level of 40 mg/dL and a normal IgA level. At 24 months, IgG remained below the lower limit of normal with an upward trend at 421 mg/dL, and IgA and IgM decreased to 14 and 29 mg/dL, respectively. Pneumococcal, tetanus and varicella vaccine titers showed protective levels.   There was rapid improvement after 1 day of intravenous acyclovir, 30 mg/kg/day in 3 divided doses. Vital signs remained normal, and he was transitioned to oral acyclovir 250 mg 3 times daily for a total course of 7 days. He was treated with topical erythromycin for comfort and prophylaxis during healing of his ocular and corneal erosions, which resolved after 1 week. There was no cutaneous scarring or post-herpetic neuralgia.  The authors considered the event to be associated with vaccine-strain varicella-zoster virus.   Upon internal review, the event Ophthalmic herpes zoster was considered as medically significant.  A copy of the published article is attached as further documentation of the patient's experience.