Source: Manual of Ambulatory Pediatrics 2010
SOAP Note – Herpes Zoster
HERPES ZOSTER
An acute viral infection affecting the dorsal root ganglion cells. It is self-limited, localized, and characterized by a vesicular eruption and neurologic pain.
I. Etiology
A. Varicella zoster virus (VZV): The primary infection results in varicella (chickenpox). After an attack of varicella, the virus remains latent in the dorsal root ganglia. Varicella is the manifestation of the VZV in a nonimmune host, and herpes zoster is the recrudescence of the latent virus in a partially immune host.
B. Susceptible children who are exposed to cases of zoster often develop chickenpox.
II. Incidence
A. Relatively rare under 10 years of age but can occur at any age
B. Seen more frequently in childhood in children who had chickenpox before age 2
C. Increased incidence in patients with malignancies or on immunosuppressive therapy
D. Approximately 65% of patients are over age 40.
III. Incubation period: 2 to 3 weeks
IV. Subjective data
A. Usually a history of varicella
B. History of itching, tenderness, or pain in area about 3 to 5 days prior to rash. Prodromal pain can be quite severe and can mimic cardiac or pleural disease, acute abdomen, or vertebral disease.
C. Rash
1. Erythematous maculopapular rash that progresses to vesicles within 24 hours
2. Generally on trunk, face, or back.
V. Objective data
A. Rash: Small, grouped vesicles on an erythematous base
B. Distribution.
1. Appears first at a point near the central nervous system along a dermatome or two adjacent dermatomes—generally posteriorly.
2. Ends at midline of body
3. Generally on trunk (over 50%), trigeminal (10%–20%), lumbosacral and cervical (10%–20%)
4. Generally unilateral; bilateral involvement is rare.
5. A few vesicles may be outside the dermatome.
C. Successive crops of lesions may appear.
D. Pain with rash is less frequent in children than in adults.
E. Occasionally a generalized rash will occur.
F. Regional lymphadenopathy
G. Sometimes a blistered burn from hot soaks used to relieve pain
VI. Assessment
A. Diagnosis is made by the distribution and characteristic appearance of the rash as well as by the associated pain. It may be confirmed by cytologic smear of vesicle.
B. Differential diagnosis
1. Coxsackieviruses: Distribution of rash differs; lesions do not crust and are not painful.
2. Multiple insect bites: Generally do not follow path of dermatome or have the characteristic appearance (small group of vesicles) or have herpetic pain
VII. Plan
A. Treatment is symptomatic.
B. Calamine lotion
C. Cool compresses with Burow’s solution (one packet dissolved in one pint of cool water, tid)
D. Acetaminophen, 10 to 15 mg/kg every 4 hours for pain (Children do not always have sensory changes, so analgesics may not be indicated.)
E. Infected lesions: Neosporin or bacitracin ointment tid
F. Zovirax capsules:
1. 800 mg 5 times daily for 7 to 10 days for children over 40 kg
2. 20 mg/kg qid for children under 40 kg
3. Start within 24 to 48 hours of appearance of dermatomal exanthem.
4. Generally not needed in childhood because pain and number of lesions are less
5. Indicated for children who are predisposed to more serious disease (e.g., immunocompromised child)
G. Bactroban or bacitracin for secondarily infected lesion. Systemic antibiotics as for Impetigo (see p. 322), if infection extensive.
VIII. Education
A. Successive lesions appear for up to 1 week.
B. Eruption usually clears in 14 to 21 days; if vesicles appear over a period of 1 week, clearing may take up to 5 weeks.
C. Lesions become pustular and dry and crust over.
D. Transmitted by both direct and indirect contact. Approximately 15% of susceptible (nonimmune) people will contract varicella.
E. Avoid exposure of children with malignancies or people on immunosuppressive therapy.
F. Postherpetic neuralgia may persist once lesions have healed.
G. There is no prevention for herpes zoster in children. (Vaccine available for people over 60 years of age.)
H. Compresses: Use cool soft cloths 4 times a day.
I. Zovirax reduces viral shedding time and the duration of new lesion formation. It also shortens the time to complete lesion scabbing, healing, and the cessation of pain.
IX. Follow-up
A. Generally not indicated for typical case
B. Return immediately if there are any symptoms of ocular involvement.
C. Recheck in 5 days if there is secondary bacterial infection.
X. Complications
A. Secondary bacterial infection
B. Rarely, ocular complications
XI. Consultation/referral
A. Patients with lesions on the tip of the nose, because there is a possibility of keratoconjunctivitis
B. Patients with hemorrhagic or bullous lesions
C. Patients with disseminated herpes zoster
D. Patients who are immunocompromised