Definition
A.Contact dermatitis is a cutaneous response to direct exposure of the skin to irritants (irritant contact dermatitis) or allergens (allergic contact dermatitis):
1.Irritant contact dermatitis is a nonimmunologic response of the epidermis.
2.Allergic contact dermatitis is an immunologic response after one or more exposures to a particular agent.
Incidence
A.Occurs in all ages. People who work with chemicals daily and wash their hands numerous times a day have a higher incidence of irritant dermatitis. Irritant contact dermatitis is seen in the elderly due to dry skin.
Pathogenesis
A.Irritant contact dermatitis is caused by an alteration of the outer layer of the dermis due to exposure to chemicals, lotions, cold, dry air, soaps, detergents, or organic solvents.
B.Allergic contact dermatitis is caused by an alteration in the epidermis when, after exposure to an allergen, the immune system responds by producing inflammation of the cutaneous tissue. Common allergens include poison ivy, poison oak, sumac, nickel jewelry, hair dye, rubber and leather chemicals (latex gloves), cleaning supplies, harsh soaps, detergents, and topical medicines.
Predisposing Factors
A.Occupation (hairdresser, nurse, housecleaner, food handlers, mechanical industry workers, etc.).
B.Jewelry.
C.Activities in yard or woods.
Common Complaints
A.Irritation of the skin, ranging from redness to pruritic inflammation, with possible progression of blisters:
1.Poison oak, ivy, and sumac induce classic presentation: lesions (vesicles) and papules on an erythemic base presenting in a linear fashion with sharp margins.
2.Diffuse pattern with erythema may be seen when oleoresin is contracted from pets or smoke from burning fire.
B.Exposure to some type of irritant known to the patient. Round or annular lesions may have an internal cause such as a drug reaction.
Other Signs and Symptoms
A.Chronic:
1.Erythema with thickening.
2.Scaling.
3.Fissures.
4.Inflammation.
5.Lichenification may occur with scales and fissures.
B.Candidiasis diaper rash:
1.Bright red rash with satellite lesions at margins.
2.Inflammation and excoriations present.
3.Creases may be involved..
Subjective Data
A.Ask the patient when irritation began and how it has progressed.
B.Elicit history of exposure to allergens.
C.Question the patient regarding activity and skin contact with irritants prior to outbreak (cleaning agents, walking in woods, hobbies, change in soap/laundry detergent, shaving cream, lotions, etc.).
D.List occupation and family history of allergens.
E.Review medication list, including prescription, over-the-counter (OTC), and herbal treatments to evaluate for an interaction.
F.List medications and OTC remedies used to relieve symptoms and results.
Physical Examination
A.Check temperature (if indicated).
B.Inspect:
1.Inspect skin, noting types of lesions and location of lesions. Note the pattern of inflammation. The shape of irritation may mimic the shape of the irritant, such as the skin under a ring or watch, for example.
2.Determine progression of lesions.
3.Differentiate between primary and secondary lesions.
Diagnostic Tests
A.Consider none if source is known.
B.Wet mount (potassium hydroxide [KOH] saline) to rule out fungal infection if candidiasis is suspected.
C.Culture/sensitivity of pustules.
D.Patch test to rule out allergic contact dermatitis.
Differential Diagnoses
A.Irritant contact dermatitis.
B.Allergic contact dermatitis.
C.Candidiasis.
D.Tinea pedis, corporis, cruris.
E.Drug reactions.
F.Pityriasis rosea.
G.Scabies.
Plan
A.General interventions:
1.Irritant contact dermatitis: Removal of irritating agent:
a.Topical soaks with saline or Burow’s solution (1:40 dilution) for weeping areas.
b.Recommend lukewarm baths (not hot) with oatmeal (Aveeno), as needed.
c.For dry erythematous skin, use Eucerin or Aquaphor ointments to rehydrate skin.
d.Remind the patient to avoid scratching skin and to keep nails short.
e.Suggest use of mild soaps and cleansers.
2.Allergic contact dermatitis:
a.Instruct the patient to avoid contact with agent.
b.Have the patient wash with cool water immediately after exposure.
c.Recommend lukewarm baths with oatmeal (Aveeno) three to four times per day.
d.Tell the patient to apply calamine lotion after baths.
B. 
See Section III: Patient Teaching Guide Dermatitis.
C.Pharmaceutical therapy:
1.Irritant contact dermatitis: Hydrocortisone 2.5% ointment three to four times per day for 2 weeks.
2.Allergic contact dermatitis:
a.Low-potency topical steroids: Hydrocortisone 2.5% ointment three to four times per day for 1 to 2 weeks after blistering stage. Triamcinolone acetonide 0.025% (Kenalog) ointment/cream twice daily.
b.Medium potency topical steroids: Triamcinolone acetonide 0.1% (Kenalog) cream twice daily.
c.High-potent topical steroids: Fluocinonide 0.05% (Lidex) ointment three to four times per day. Not to be used on face or skin folds.
d.Hydroxyzine 25 to 50 mg four times daily, diphenhydramine (Benadryl) 25 to 50 mg four times daily.
e.If rash is severe (face, eyes, genitalia, mucous membranes), consider prednisone 60 to 80 mg/d to start and taper over 10 to 14 days.
f.Triamcinolone acetonide (Kenalog) 40 to 60 mg by intramuscular (IM) injection.
3.Secondary bacterial infections: Erythromycin 250 mg four times daily or amoxicillin, clavulanate acid (Augmentin) 875 mg twice daily for 10 days.
4.Secondary candidiasis infections:
a.Miconazole nitrate 2% cream, miconazole powder, or nystatin cream.
b.Clotrimazole (Lotrimin) or ketoconazole (Nizoral) cream three to four times per day for 10 days.
c.If inflammation is present along with yeast, use Mycolog II.
d.If secondary bacterial infection is present, use mupirocin (Bactroban) ointment three times daily for 7 to 10 days.
Follow-Up
A.None is required if case is mild.
B.See patient again in 2 to 3 days for severe cases, or phone to assess progress.
Consultation/Referral
A.Consult with a physician when steroid treatment is necessary or if worsening symptoms develop despite adequate therapy.
Individual Considerations
A.Pregnancy: If medications are necessary during pregnancy, consider gestational age of fetus and category of medication.
B.Geriatrics:
1.Patients may only exhibit scaling as the prominent irritation rather than erythema and inflammation. Topical medications (neomycin, vitamin E, lanolin) and acrylate adhesives are common causes of contact dermatitis.
2.Avoid first-generation anticholinergics because of risk of confusion, dry mouth, constipation, and other anti-cholinergic effects or toxicity.
3.Pruritus that persists ≥6 weeks in elderly population 65 years old and older is considered a chronic dermatitis condition. Studies indicate that the aging epidermal barrier, nervous system, and immune system predispose geriatrics to a sensation of itchiness.
Topical medications are considered first-line treatment for geriatrics; however, systemic treatments might be considered after evaluation of the patient’s comorbid diseases.