Allergic Contact Dermatitis

Clinical Cases

Case 1

  • 8-year-old healthy boy, develops pruritic peri-orbital rash
  • No new medications, soaps, lotions
  • Started swimming classes two weeks ago, uses new swim goggles with rubber padding. On further history, the child’s parents endorse a history of rashes of unknown cause, in which exposure to rubber products was suspected.
  • On exam, he has bilateral peri-orbital edema, erythema and mild eczematous changes
  • A diagnosis of allergic contact dermatitis is given


  • Hydrocortisone 2.5% cream applied b.i.d. for several days, replace swim goggles with a pair with non-rubber padding
  • Educational materials on allergic contact dermatitis, rubber allergy is given
  • Follow-up in one week

One-week follow-up visit

  • Rash is resolved
  • Hydrocortisone is discontinued
  • Given history of possible recurrent allergic contact dermatitis, recommend limited patch testing to different types of rubber and chemicals utilized in rubber processing; this testing is done several weeks later, and a positive reaction to mercaptobenzothiazole (a chemical accelerant used in the processing of rubber) is confirmed

Case 2

  • 18-year-old healthy student with a intensely-pruritic rash present for 7 days on arms, legs
  • Went camping last week in a forested area known to have poison oak; no other known exposures; another member of the camping group has similar rash on legs
  • Exam: Bright erythema with overlying vesicles, several linear streaks of erythema and fine vesiculation noted on the arms; no mucosal or genital involvement
  • Diagnosis: Rhus dermatitis (allergic contact dermatitis to poison oak)
  • Treatment: triamcinolone 0.1% cream b.i.d., aluminum acetate compresses daily, hydroxyzine 25mg taken in the evening for pruritus
  • Follow-up in 2 weeks (resolved)

Case 3

  • 42-year-old woman who develops pruritic rash on lateral cheeks, neck, and shoulders ten days after dying her hair
  • No other new cosmetics, shampoos, conditioners, lotions, or medications
  • Exam: brightly erythematous, eczematous plaques on the lateral cheeks, lateral aspects of the neck, upper shoulders, V-neck chest
  • Diagnosis: allergic contact dermatitis to hair dye chemical
  • Treatment: desonide 0.05% cream applied b.i.d., aluminum acetate compresses b.id., hydroxyzine 25 mg at bedtime for nighttime pruritus
  • Follow-up in 3 weeks

Three-week follow-up evaluation

  • Clinically improved, but still with faintly erythematous, eczematous patches in the same distribution
  • Patient reports ongoing pruritus
  • Treatment: recommend ongoing topical treatment, with limited patch testing ordered to common hair cosmetic chemicals

Patch testing results

  • A limited patch testing series of common hair cosmetic chemicals is performed, revealing a reaction to paraphenylenediamine (PPDA)
  • Educational materials and counseling on products containing PPDA is given