Snapshot A 17-year-old girl presents to her primary care physician with symmetric swollen eyes. On further questioning, she reveals that she recently changed her brand of eye shadow. On exam, only her upper eyelids are erythematous with vesicles. She is instructed to stop the eyeshadow immediately. Given the sensitive nature of eyelids, she is given petroleum jelly to soothe the contact dermatitis. She is reassured that this will resolve. Introduction Clinical definition erythematous and pruritic rash caused by cutaneous exposure to allergens most common form of contact dermatitis to irritants often involves hands often from occupational exposures Epidemiology Demographics female > male Risk factors exposure to potential allergens or irritants occupations with higher risk of contact dermatitis healthcare food production cosmetics farming Etiology Pathogenesis allergic contact dermatitis immunologic reaction to allergen causing type IV hypersensitivity reaction delayed T-cell mediated reaction activation of Th1 cells memory CD4+ cells are created and dermatitis develops upon re-exposure or cross-reaction irritant contact dermatitis nonimmunologic reaction to substance that causes direct damage to the skin release of inflammatory cytokines activated by non-immune pathways Most common allergens include poison ivy poison oak poison sumac nickel Most common irritants include chemicals alcohol creams Presentation Symptoms presents 12-48 hours after exposure to allergen presents minutes to hours after exposure to irritant pruritic burning or stinging Physical exam linear or geometric rash, corresponding to topical exposure, composed of papules and vesicles can progress to blisters and bullae for example, patients allergic to the adhesive in a bandaid will present with a square or rectangular-shaped rash eczematous rash lichenification fissuring scaling Studies Labs none Patch testing to identify potential allergens to help prevent future exposures Histology spongiosis Differential Atopic dermatitis Treatment Conservative skin moisturizer indication decrease irritation in nonimmunologic contact dermatitis Medical topical corticosteroids indication localized or mild-to-moderate disease first-line therapy topical tacrolimus indication when corticosteroids are contraindicated systemic corticosteroids indications widespread or severe disease disease that involves mucosa Comlications Postinflammatory hypo- or hyperpigmentation Secondary bacterial infection Prognosis Typically resolves with treatment
QUESTIONS 1 of 3 1 2 3 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M2.DM.17.4769) A 25-year-old woman with no prior medical history presents with complaints of a new skin rash. She was in her usual state of health until one month ago when she began developing an itchy rash on her lower abdomen. The patient works as a fitness instructor. Her family history is notable for a father with psoriasis and a brother with atopic dermatitis. Physical exam is notable for an otherwise healthy-appearing female and Figure A on skin exam. Her temperature is 98.9°F (37.2° C), pulse is 80/min, blood pressure is 120/82 mmHg, respirations are 10/min, and O2 saturation is 99% on room air. Her laboratory results are as follows:Serum:Na+: 135 mEq/LK+: 4.2 mEq/LHCO3-: 25 mEq/LCl-: 100 mEq/LBUN: 19 mg/dLCreatinine: 1.0 mg/dLGlucose: 94 mg/dLHemoglobin: 14.4 g/dLLeukocyte count: 10,000 cells/mm^3Platelet count: 380,000/mm^3Which of the following is the mechanism underlying this patient’s skin findings? QID: 109137 FIGURES: A Type & Select Correct Answer 1 IgE-mediated hypersensitivity 19% (5/26) 2 Immune complex-mediated hypersensitivity 4% (1/26) 3 T-cell-mediated hypersensitivity 62% (16/26) 4 Fungal infection 8% (2/26) 5 Deficiency of filaggrin 8% (2/26) M 6 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (M2.DM.14.25) A 20-year-old man presents to his primary care physician complaining of intense itching on the back of his left calf. He states that he noticed a red and blistering rash this morning and does not recall experiencing a similar rash in the past. His social history is notable for a job at the zoo. His temperature is 97.7°F (36.5°C), blood pressure is 120/74 mmHg, pulse is 70/min, respirations are 14/min, and oxygen saturation is 98% on room air. His physical exam is notable for the finding in Figure A. Which of the following findings would be found in the most likely diagnosis? QID: 103818 FIGURES: A Type & Select Correct Answer 1 Acanthosis 50% (51/103) 2 Caseating granulomas 1% (1/103) 3 Extraepidermal vesicles with keratinocytes 8% (8/103) 4 Langerhans giant cells 8% (8/103) 5 Spongiosis 32% (33/103) M 6 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic