|
|
Features Departments Information |
 Anthony J. Mancini, MD
|
Dermatology quiz ANTHONY J. MANCINI, MD aFall 1998 A SEVEN-YEAR-OLD African-American male presents with a two-month history of an extremely pruritic rash on the abdomen. Treatment with topical 1% hydrocortisone cream and oral diphenhydramine hydrochoride has led to mild improvement in symptoms but persistence of the rash. His parents deny any known infectious exposures or recent travels, and review of systems is otherwise unremarkable. Past medical history is notable for seasonal allergies, and his family history is positive for atopy. Examination reveals multiple erythematous lichenified papules coalescing into a large plaque on his inferolateral periumbilical area (Figures 1 and 2). The remainder of the examination is notable only for diffuse xerosis and mild follicular prominence.   FIGURES 1, 2. The most appropriate next step is to: A. Perform a skin biopsy for diagnostic confirmation.
The most appropriate therapy includes: A. Permethrin cream for the patient and his entire family.
Preventive strategies include the use of all of the following EXCEPT:
A. Clear nail polish.
Answers: C, B, and B, respectively The patient depicted had a classic allergic contact dermatitis to nickel, in this case most likely related to contact with metal snaps, zippers, or belt buckles. Nickel is a leading cause of allergic contact dermatitis and is responsible for more cases than all other metals combined.1 The presentation of nickel dermatitis is similar to that of any allergic contact dermatitis. Patients frequently have erythematous, eczematous eruptions at sites of contact and may develop vesicles, oozing, and crusting. The eruption is characteristically extremely pruritic. Lichenification, which appears as thickening of the skin with prominent skin markings, is the result of chronic rubbing in areas frequently exposed to the allergen. Hyperpigmentation may also develop, especially in patients with darker native skin complexions. The distribution of lesions is usually quite helpful in suggesting the diagnosis. Common sites of involvement include pierced earlobes, the suprapubic and umbilical regions, and areas of skin underneath rings, bracelets, necklaces, and wristwatches. In infants, nickel dermatitis may be present due to contact sensitization by nickel found in metal snaps present on undershirts.2 Diagnosis of allergic contact dermatitis to nickel is usually made on a clinical basis, although testing reagents are found in most standard patch test trays if confirmation is required. Presence of nickel in metal products can also be confirmed by the application of dimethylglyoxime, which turns nickel-containing objects orange-pink. Nickel is one of the most common allergens implicated in pediatric allergic contact dermatitis,3–5 although the exact frequency is difficult to ascertain given the rarity of patch testing performed in children. While the practice of ear piercing probably accounts for a significant portion of nickel sensitization in children,6,7 allergic contact dermatitis to the metal has been reported in all pediatric age groups, including infants, where it may be more common in those with an atopic diathesis.8 A recent report of 670 patch-tested pediatric patients (>12 years of age) revealed that 52 (7.76%) were positive to nickel, of which 29 were girls with pierced ears.9 Prophylactic measures in the prevention of nickel dermatitis include avoiding contact with the allergen, either through avoidance of exposure to items containing nickel or nickel plating, or prevention of direct contact between such items and the skin. The latter can be accomplished by a variety of methods, such as tucking shirts into pants so as to avoid contact of metal snaps, buttons, or zippers with the periumbilical or suprapubic skin; using plastic sheathes over earring posts; and coating the contact surfaces of nickel containing items with several applications of clear nail polish. Once dermatitis has developed, therapy with topical corticosteroids, cool compresses, oral antihistamines and antibiotics (if necessary), in addition to elimination of further exposure to the allergen, usually suffices. REFERENCES 1. Arnold HL, Odom RB, James WD (eds.): Andrews' Diseases of the Skin. In Clinical Dermatology, 8th edition. Philadelphia: W.B. Saunders Co., 1990. 2. Krafchik BR: Eczematous dermatitis. In Pediatric Dermatology, 2nd edition. Schachner LA, Hansen RC (eds.) New York: Churchill Livingstone Inc., 1995. 3. Kuiters GR, Smitt JH, Cohen EB, Bos JD: Allergic contact dermatitis in children and young adults. Arch Dermatol 1989;125(11):1531–33. 4. Sevila A, Romaguera C, Vilaplana J, Botella R: Contact dermatitis in children. Contact Dermatitis 1994;30(5):292–294. 5. Veien NK, Hattel T, Justesen O, Norholm A: Contact dermatitis in children. Contact Dermatitis 1982;8(6):373–375. 6. Christensen OB: Nickel dermatitis. An update. Dermatol Clin 1990;8(1):37–40. 7. Larsson-Stymne B, Widstrom L: Ear piercing-A cause of nickel allergy in schoolgirls? Contact Dermatitis 1985;13(5):289–293. 8. Ho VC, Johnston MM: Nickel dermatitis in infants. Contact Dermatitis 1986;15(5):270–273. 9. Manzini BM, Ferdani G, Simonetti V, Donini M, Seidenari S: Contact sensitization in children. Pediatric Dermatol 1998;15(1):12–17. |