Kamis, 29 November 2007

Acropustulosis of Infancy

Background: Infantile acropustulosis is a recurrent, self-limited, pruritic, vesicopustular eruption of the palms and the soles occurring in young children during the first 2-3 years of life. Newly described in 1979, it is probably much more common than the scarcity of reports would imply.

Pathophysiology: The pathophysiology of infantile acropustulosis is unknown. Many cases are preceded by well-documented or suspected scabies infestation, and a scabies id reaction has been suggested. More often, cases occur despite scabies having been thoroughly ruled out. Bacterial and viral culture results are consistently negative, and negative immunofluorescence results suggest that infantile acropustulosis is not an antibody-mediated autoimmune process.

Frequency:

  • In the US: The exact incidence is unknown.
  • Internationally: The exact incidence is unknown. One study from Israel reported 25 cases in a 9-year period, suggesting that this is not as uncommon as once thought.

Mortality/Morbidity: All cases spontaneously resolve in a few months to 3 years.

Race: Early reports suggested a predominance of African Americans. Now, acropustulosis is believed to affect all races equally.

Sex: Early reports suggested a male predominance. Larger series have since shown an equal distribution between males and females.

Age: Although children as old as 9 years have been reported, acropustulosis typically begins between the first 2-12 months of life. Resolution by age 3 years is the norm.

Treatment
Medical Care: Treatment is often unnecessary because of the self-limited nature of this condition.
  • Topical steroids and oral dapsone have been used successfully, if justified in more difficult cases.
  • Topical pramoxine preparations are available without prescription for the treatment of pruritus.
  • Oral antihistamines may be useful.

Consultations: Consult a dermatologist or a pediatric dermatologist.

Activity: Isolation is not warranted.

Medication
High-potency topical steroids (classes 1 and 2) have been used successfully for control of pruritus. Children who are extremely symptomatic may be treated with dapsone.
Drug Category: Topical steroids -- These agents provide symptomatic relief of pruritus.
Drug Name
Betamethasone (Diprolene, Betatrex) -- For inflammatory dermatoses responsive to steroids. Decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing capillary permeability. Use fluorinated topical steroids with caution in children.
Pediatric DoseApply thin film to affected areas bid; occlusion increases effectiveness; avoid wraps that may present choking hazard
ContraindicationsDocumented hypersensitivity; paronychia; cellulitis; impetigo; angular cheilitis; erythrasma; erysipelas; rosacea; perioral dermatitis; acne
InteractionsNone reported
Pregnancy C - Safety for use during pregnancy has not been established.
PrecautionsApplication over large surface areas may cause systemic absorption and adrenal suppression; do not use on skin with decreased circulation; can cause atrophy of groin, face, and axillae; if infection develops and is not responsive to antibiotic treatment, discontinue until infection is under control
<Drug Category: Antibiotics -- Diaminodiphenylsulfone antibiotics have been used as anti-inflammatory agents.
Drug Name
Dapsone (Avlosulfon) -- Bactericidal and bacteriostatic against mycobacteria; mechanism of action is similar to that of sulfonamides where competitive antagonists of PABA prevent formation of folic acid, inhibiting bacterial growth. Used mainly to treat leprosy and dermatitis herpetiformis. Has antineutrophil and anti-inflammatory properties.
Pediatric Dose1-2 mg/kg/d PO; not to exceed 100 mg
ContraindicationsDocumented hypersensitivity; known G-6-PD deficiency (assay for G-6-PD activity prior to initiation of therapy)
InteractionsMay inhibit anti-inflammatory effects of clofazimine; hematologic reactions may increase with folic acid antagonists, eg, pyrimethamine (monitor for agranulocytosis during second and third months of therapy); probenecid increases toxicity; trimethoprim with dapsone may increase toxicity of both drugs; because of increased renal clearance, levels may significantly decrease when administered concurrently with rifampin
Pregnancy C - Safety for use during pregnancy has not been established.
PrecautionsAssociated with a variety of systemic toxicities, including agranulocytosis, anemia, methemoglobinemia, hepatitis, and neuropathy; patients may experience headache and/or GI distress on initiation of therapy; perform weekly blood counts (first mo), then monthly WBC counts (6 mo), then semiannual WBC counts; discontinue if a significant reduction in platelets, leukocytes, or hematopoiesis occurs; caution in methemoglobin reductase deficiency, G-6-PD deficiency, or hemoglobin M because of high risk for hemolysis and Heinz body formation
Caution in patients exposed to other agents or conditions (eg, infection, diabetic ketosis) capable of producing hemolysis; peripheral neuropathy can occur (rare); phototoxicity may occur when exposed to UV light; pancreatitis may occur; various forms of renal complications including acute renal failure, acute tubular necrosis, and oliguria have occurred with dapsone use
<Drug Category: Antipruritics -- These agents may relieve associated itching.
Drug Name
Pramoxine (Tronothane, Prax) -- Blocks nerve conduction and impulses by inhibiting depolarization of neurons. Use 1% lotion or cream.
Pediatric DoseApply to affected area prn; not to exceed 200 mg
ContraindicationsDocumented hypersensitivity; do not apply over large areas; avoid contact with eyes and nose
InteractionsNone reported
Pregnancy C - Safety for use during pregnancy has not been established.
PrecautionsCaution in patients with trauma in area to be treated