– An acute, viral, communicable disease characterized by clusters of maculopapular skin eruptions that become vesicular and produce a granular scab.
Causes and Incidence
The cause is the varicella-zoster virus, which invades the body through the respiratory membranes. Chicken pox is a common childhood illness, with susceptibility typically extending from 6 months of age to the time the disease is contracted. Epidemics occur in the winter and early spring in 3- to 4-year cycles. Immunity is produced after a course of the disease.
The virus enters the body by means of direct droplet contact through the respiratory system. The incubation period is 2 to 3 weeks before localized and systemic signs and symptoms appear. The person is considered infectious from the time of exposure until the final lesions crust over. After recovery, the virus is believed to remain in the body in a dormant or latent state in the dorsal root ganglia. Reactivation of the infection in adulthood manifests itself as shingles.
The first signs and symptoms are mild headache, low-grade fever, malaise, and anorexia, which occur about 24 hours before the first rash appears. The initial rash, which is maculopapular, appears on the head and mucous membranes and evolves within hours to itching, teardrop-shaped vesicles containing a clear fluid. The vesicles break and crust over within 6 to 8 hours. New lesions erupt in successive crops on the trunk and in sparse sprinkles on the extremities. The acute phase of the disease lasts 4 to 7 days, and new lesions seldom appear after the fifth day. All lesions are generally healed in 2 to 3 weeks.
The disease may be severe in adults or in individuals whose T-cell immunity is depressed or who are taking corticosteroids or undergoing chemotherapy. Complications include conjunctival ulcers, encephalitis, meningitis, thrombocytopenia, secondary abscesses, cellulitis, pneumonia, sepsis, Guillain-Barre syndrome, and Reye’s syndrome. Scratching of the lesions may cause scarring and disfigurement.
Diagnosis depends primarily on clinical examination of the characteristic lesions. Giemsa-stained scrapings from the lesions will show multinucleated giant cells, and a culture of vesicular fluid will grow the varicella-zoster virus.
Surgery – None.
Antihistamines, topical steroids to relieve itching; acyclovir or zoster immune globulin after exposure in high-risk individuals; vaccine for prevention; no salicylates (aspirincontaining drugs).
Baking soda paste or calamine lotion on lesions to relieve itching; isolation until lesions crust; trimming of nails and use of mittens to prevent scratching of lesions; cool room and distractions to lessen focus on itching.