Painful rash on face

Diagnosis: Herpes zoster ophthalmicus

An ophthalmologic exam confirmed the diagnosis of herpes zoster ophthalmicus (HZO), a serious condition that has been linked to reactivation of the varicella-zoster virus (VZV) within the trigeminal ganglion.¹ Primary infection with VZV results in varicella (chickenpox), whereas reactivation of a latent VZV infection within the sensory ganglia is known as herpes zoster.

HZO occurs in 10% to 20% of patients who have herpes zoster.² The ophthalmic division of the trigeminal nerve is most frequently involved, and as many as 72% of patients experience direct ocular involvement.¹

Herpes zoster ophthalmicus begins with headache, fever, and unilateral pain in the affected eye, followed by a vesicular eruption along the trigeminal dermatome.

The acute syndrome begins with headache, fever, and unilateral pain in the affected eye, followed by the onset of a vesicular eruption along the trigeminal dermatome, hyperemic conjunctivitis, and episcleritis.^3,4 Almost two-thirds of HZO patients develop corneal involvement.⁵

Rule out other types of vesicular eruptions

Impetigo, herpes simplex virus-type 1 (HSV-1), atopic dermatitis, acute contact dermatitis, and chickenpox should be included in the differential diagnosis of HZO.

Impetigo is a superficial bacterial infection. The lesions begin as papules and then progress to vesicles that enlarge and rapidly break down to form adherent crusts with a characteristic golden appearance. These lesions usually affect the face and extremities.

HSV-1 is characterized by multiple vesicular lesions superimposed on an erythematous base on the skin or mucous membranes of the mouth or lips.

Atopic dermatitis is characterized by pruritus, erythema, scale, and crusting. The flexural areas (neck, antecubital fossae, and popliteal fossae) are most commonly affected.⁶ Other common sites include the face, wrists, and forearms.

Acute contact dermatitis is an acute vesicular eruption accompanied by pruritus and erythema. The vesicles may be distributed in a characteristic linear pattern when a portion of an allergen (such as poison ivy) has made contact with the skin or when the patient has scratched the skin.

Chickenpox is a primary infection with VZV. The clinical manifestations include a prodrome of fever, malaise, or pharyngitis, followed by the development of a generalized vesicular rash. Although the appearance of the chickenpox rash is similar to that of HZO, herpes zoster is usually localized to a dermatome.

Diagnostic testing is rarely indicated

A history of VZV infection and the characteristic rash are usually adequate to make a diagnosis of HZO. Of note: vesicular lesions on the nose—known as Hutchinson’s sign—are associated with a high risk of HZO.⁷

If you suspect HZO, your patient will need an ophthalmologic exam, including an external inspection, testing of visual acuity, extraocular movements, and pupillary response, and various other exams (fundoscopy, anterior chamber slit lamp, and corneal).

A viral culture, direct immunofluorescence assay, Tzanck smear, or polymerase chain reaction may be used to confirm the diagnosis.