Week 9 Dermatology CD Fungal Infections

Contact Dermatitis and Fungal Skin Infections

• Presenter: Nadia Khartabil, PharmD, BCGP, Aph, MAS

• Institution: WCU- School of Pharmacy

Learning Objectives

• Compare and contrast irritant and allergic contact dermatitis.

• Recognize common irritants causing irritant contact dermatitis.

• Distinguish sources of allergic contact dermatitis.

• Describe the role of urushiol oleoresin in allergic contact dermatitis.

• Recommend appropriate treatments for both types of dermatitis.

• Distinguish dosage forms and considerations for topical treatments.

• Identify treatment goals for irritant contact dermatitis, allergic contact dermatitis, and fungal infections.

• Recognize exclusion factors for each condition.

• Describe the pathophysiology and clinical presentation of fungal infections.

• Identify mechanisms of action for self-treatment products for fungal infections.

• Recommend treatments based on clinical presentation.

Contact Dermatitis (CD)

Types of Contact Dermatitis

• Irritant Contact Dermatitis (ICD):

  • Inflammatory skin reaction due to irritants.

  • Direct damage to epidermal cells (non-immune response).

• Common in occupations like dishwashing, food handling, and health services. - Symptoms include macerated, inflamed skin confined to contact area.

• Allergic Contact Dermatitis (ACD):

  • Immunologic reaction to antigens.

  • Symptoms may not appear until re-exposure.

Irritant Contact Dermatitis (ICD)

Epidemiology and Etiology

• Affects approximately 1% of the population.

• Common in workers frequently exposed to irritants.

Pathophysiology

• Direct absorption causing irritation and cytokine release.

• Non-immune-related irritation.

Common Irritants

• Strong acids, alkalis, detergents, fiberglass, oils, radiation, solvents.

Clinical Presentation

• Characterized by well-demarcated, painful, inflamed skin.

Treatment Goals

1. Remove the offending agent.

2. Provide prompt treatment.

3. Relieve inflammation.

4. Educate to prevent recurrence.

ICD Treatment Approach

Pharmacological Treatment

• Burrow’s solution (5% aluminum acetate): Anti-inflammatory, antibacterial.

• Petrolatum: Prevents epidermal water loss.

• Colloidal oatmeal: Alleviates itching.

• Topical corticosteroids: Usage is questionable.

• Avoid anesthetics (-caine types).

Nonpharmacological Treatment

• Wash the area with lukewarm water.

• Use mild hypoallergenic soap (e.g., Cetaphil).

• Consider saline soak (1 tsp salt + 1 pint water).

• Use protective clothing and barrier creams.

Allergic Contact Dermatitis (ACD)

Epidemiology and Etiology

• Accounts for 10-20% of contact dermatitis cases.

• Common allergens include poison ivy, nickel, latex, and fragrances.

Pathophysiology

• Type IV delayed hypersensitivity: Requires initial exposure followed by sensitization.

Urushiol-Induced ACD

• Sensitivity to urushiol from poison ivy, oak, sumac.

• Majority (80%) of the U.S. population susceptible to urushiol.

• Symptoms typically appear within 24-48 hours of exposure.

Treatment Goals

1. Remove contact with the offending agent.

2. Treat inflammation and itching.

3. Prevent secondary infections.

Preventive Measures for ACD

• Learn characteristics and habitats of Toxicodendron plants.

• Use protective clothing when eradicating these plants.

• Avoid burning plant materials.

Fungal Infections

Overview

• Affects 20-25% of the world's population.

• Includes superficial infections of hair, nails, and skin.

• Can arise from diabetes, immune issues, and other risk factors.

Types of Fungal Infections

• Dermatophyte infections (most common).

• Types include Tinea Pedis, Tinea Corporis, Tinea Capitis, Tinea Cruris, Tinea Unguium.

Clinical Presentation of Fungal Infections

• Tinea Pedis: Commonly known as Athlete's foot, involves feet.

• Tinea Corporis: Ringworm on the body, circular itchy lesions.

• Tinea Capitis: Scalp infections with papules or kerions.

• Tinea Cruris: Jock itch localized to groin and thighs.

• Tinea Unguium: Nail infections that may cause thickening and separation.

General Treatment Approach

Treatment Goals

• Provide symptomatic relief, eradicate infection, prevent future infections.

Non-pharmacological Therapy

• Keep skin dry, avoid sharing towels, wear cotton socks, avoid occlusive footwear.

When to Refer

• Patients with systemic infections, extensive inflammation or secondary infections require referral.

Nonprescription Medications

• Available options: undecylenic acid, butenafine, clotrimazole, miconazole, terbinafine, tolnaftate.

• Treatment duration typically ranges from 2-6 weeks.

Patient Education

Nondrug Measures

• Prevent spreading the infection by using personal towels, laundering contaminated items.

• Pad dry to keep skin breathable, apply antifungals as directed.

Medication Application

• Apply keratolytic agents for effective penetration in thick skin areas before antifungals.

• Use aluminum acetate solution for wet, oozing areas before antifungal treatments.

References

• Handbook of Nonprescription Drugs, Chapter 35 & 42.