This 4-year-old boy (http://www.idinchildren.com/200604/spot.asp) presented to the office with a history of crusting and drainage of the surface of the nose for several weeks. His parents said the lesion initially looked like a mosquito bite and then progressed to its appearance at the time of presentation.

Previously, a simple wound culture for bacteria was negative. He had been treated with antibiotics and prednisone with little or no improvement. The lesion has continued to spread slowly. He lives on a farm in Indiana. His family owns a few livestock, chickens and two cats.

The child’s physician sent fresh tissue from a biopsy for culture and grew Sporothrix schenckii.

S. schenckii is a dimorphic fungus, which grows as an oval or cigar-shaped yeast 98.6°F. It can be found in soil, hay, straw, thorny plants (especially roses), sphagnum moss and decaying vegetation.

Cutaneous sporotrichosis is the most common manifestation of an infection with S. schenckii. Inoculation occurs in the presence of a minor break in the skin. After one to 12 weeks, a painless nodule, which is typically red or violaceous, appears at the site of the inoculation. More nodules develop, and these tend to open, ulcerate and drain. Pulmonary and disseminated forms of sporotrichosis can be seen in immunocompromised patients.

Differential diagnoses for this condition should include herpes, mycetoma, blastomycosis, chromoblastomycosis, mycobacterium infections and discoid lupus.

Our patient was treated for three months with saturated solution of potassium iodide. He healed with scarring. Itraconazole is approved for treatment of cutaneous and lymphocutaneous sporotrichosis in adults; however, the 2003 Red Book states: “Although there are no controlled trials to document the efficacy of itraconazole in pediatric patients, most experts consider itraconazole the preferred treatment”.

Immunocompromised patients with disseminated sporotrichosis often require treatment with amphotericin B.

Recommendations for prevention include wearing gloves and long sleeves when working with materials where the fungus can be found.

This 11-month-old boy (http://www.idinchildren.com/200603/spot.asp) presented with a four-day history of vesicular rash with erosions and desquamation. The rash initially appeared on his trunk, then progressed to the rest of his body. His review of systems was positive for fever (101.8ºF) and irritability, as well as cough and rhinorrhea one week prior to presentation. He received either acetaminophen (Tylenol, Ortho-McNeil) or ibuprofen for his fever, according to his mother’s history. He has a sister who was seen about two weeks prior for a skin eruption on her arm, which was diagnosed as pityriasis rosea. What do you think is the diagnosis?

This patient had varicella with superimposed Staphylococcus aureus. An initial Tzanck test was negative. His cultures were positive for methicillin-sensitive S. aureus. He was initially treated with IV acyclovir, clindamycin, oxacillin and vancomycin. Oral acyclovir, linezolid (Zyvox, Pfizer) and cephalexin were administered when the diagnoses of varicella and S. aureus were made.

Varicella zoster virus is a herpes virus responsible for varicella (chickenpox) and herpes zoster (shingles). Varicella occurs in 90% of U.S. children before age 10 years. The incubation period may last 14 to 16 days, with a one- to three-day prodrome consisting of fever, respiratory symptoms and headache, especially in older patients. The exanthem consists of pruritic red macules that rapidly develop into vesicles with surrounding erythema, giving the characteristic “dew drop on a rose petal” appearance; these then form pustules that scab over. The lesions are typically found on the trunk and face; however, the scalp and mucosal surfaces may also become involved.

The most common complication is secondary bacterial infection (2% to 3% of children) with staphylococci or group A streptococci. Staphylococcal infections may be toxin-mediated (scalded skin syndrome, toxic shock syndrome) or suppurative (impetigo, abscesses). Other complications from varicella include encephalitis, thrombocytopenia, arthritis, hepatitis, cerebellar ataxia, meningitis and glomerulonephritis. Immunocompromised patients may develop varicella pneumonia or hemorrhagic varicella lesions.

Transmission occurs most commonly through respiratory droplets. Infection through direct contact with vesicular fluid is also possible.

Varicella is usually diagnosed clinically from the history and physical. Tzanck smear from an intact vesicle may demonstrate multinucleated giant cells. The diagnosis may also be made from direct fluorescent antibody staining or viral culture of fluid from a fresh vesicle.

The differential diagnosis includes herpes simplex virus, vesicular viral exanthems (coxsackie, enterocytopathic human orphan), impetigo, papular urticaria, scabies, drug eruption, contact dermatitis or folliculitis.

Treatment consists of supportive measures such as antipyretics, antihistamines, calamine lotion and tepid baths. Salicylates should be avoided due to the risk of Reye’s syndrome. Acyclovir given within 24 to 72 hours after onset of rash can result in a modest decrease in duration and symptoms. IV acyclovir is indicated for immunocompromised patients or high-risk neonates. Oral acyclovir should be reserved for immunocompetent patients at increased risk of moderate-to-severe varicella. Famciclovir (Famvir, Novartis) and valacyclovir (Valtrex, GlaxoSmithKline) are other antiviral agents licensed for treatment of adults; safety and efficacy, however, have not been established in children.

The varicella vaccine is more than 95% effective in preventing moderate-to-severe disease, and 70% to 85% effective in preventing mild disease. Recommendations for vaccination are one dose in children 12 years of age or younger, or two doses four to eight weeks apart in patients older than 12. About 1% to 4% of vaccinated children may develop a mild varicellalike reaction consisting of insect bitelike papules, low-grade fever and rapid recovery.

For more information:

• Bolognia, JL, Jorizzo J, Rupini R. Dermatology. Vol.1. Philadelphia, PA: Mosby; 2003: 1241-1243.
• Pickering LK, ed. Staphylococcal infections. In: American Academy of Pediatrics. Red Book: 2003 Report of the Committee on Infectious Diseases. 26th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2003: 573-574, 672-683.
• Pickering LK, ed. Varicella-zoster infections. In: American Academy of Pediatrics. Red Book: 2003 Report of the Committee on Infectious Diseases. 26th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2003: 672-683.