What are the treatment options for dermatitis and dermatophytosis?

Treatment of Dermatitis and Dermatophytosis

Dermatitis Treatment

For contact and atopic dermatitis, topical corticosteroids are the primary first-line pharmacologic treatment, with potency selection based on severity and anatomic location. 1, 2

First-Line Approach for Dermatitis

• Identify and eliminate the causative allergen or irritant - this is the most critical step for successful treatment 1
• Apply topical corticosteroids as the cornerstone of therapy:
  • Use low-potency steroids (hydrocortisone) for face, neck, and skin folds to prevent skin atrophy 1
  • Use mid-to-high potency steroids for trunk and extremities 1
  • Apply twice daily to affected areas 1
• Replace all soaps and detergents with emollients - this restores skin barrier function even when not the direct cause of dermatitis 1, 3
• Apply moisturizers liberally after bathing and hand washing 2, 3

Potency Selection Algorithm

• Mild dermatitis: Low-potency topical corticosteroids plus emollients 2
• Moderate dermatitis: Medium-potency topical corticosteroids plus emollients, with consideration of proactive maintenance therapy 2
• Severe dermatitis: High-potency topical corticosteroids, short-term systemic corticosteroids, and patch testing to identify specific allergens 1

Second-Line Steroid-Sparing Agents

• Topical calcineurin inhibitors (tacrolimus, pimecrolimus) are effective alternatives, particularly for sensitive areas like the face and for long-term maintenance therapy 1, 2, 4
• These agents avoid the skin atrophy risk associated with prolonged corticosteroid use 4

Advanced Therapies for Refractory Cases

For atopic dermatitis unresponsive to topical therapy:

• Phototherapy (narrowband UVB preferred) should be added for severe or refractory disease 2
• Systemic therapies for very severe cases include:
  • Dupilumab (FDA-approved for ages 6 months and older) 2
  • JAK inhibitors (abrocitinib, baricitinib, upadacitinib) 2
  • Tralokinumab 2

Critical Pitfalls to Avoid

• Do not use topical antibiotics long-term - they increase resistance risk and can cause allergic contact dermatitis themselves 1, 3
• Avoid topical antihistamines - limited efficacy and may cause contact dermatitis 1
• Do not rely on barrier creams alone - they provide questionable protection and create false security 1
• Systemic antibiotics should only be used when clinical bacterial infection is present, not for uncomplicated dermatitis 2, 3

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Dermatophytosis Treatment

For dermatophyte infections of skin, hair, and nails, oral antifungal therapy with terbinafine or griseofulvin is indicated when topical therapy is inadequate or the infection involves hair/nails. 5, 6

Diagnosis Confirmation Required

• Obtain appropriate specimens (KOH preparation, fungal culture, or nail biopsy) before initiating treatment to confirm dermatophyte infection 5, 6
• This prevents unnecessary treatment of non-dermatophyte conditions 5

Treatment Selection by Site

For tinea corporis, tinea pedis, tinea cruris (skin only):

• Topical antifungals may be sufficient for mild cases 7
• Oral therapy indicated when topical treatment fails 5

For tinea capitis (scalp) and tinea unguium (nails):

• Oral antifungal therapy is required - topical agents are inadequate 5, 7

Oral Antifungal Regimens

Terbinafine (preferred for most dermatophytoses):

• Fingernail onychomycosis: 250 mg once daily for 6 weeks 6
• Toenail onychomycosis: 250 mg once daily for 12 weeks 6
• Optimal clinical effect occurs months after treatment completion as healthy nail grows out 6

Griseofulvin (alternative agent):

• Effective against Trichophyton, Microsporum, and Epidermophyton species 5
• Indicated for dermatophyte infections of skin, hair, and nails not adequately treated by topical therapy 5

Critical Monitoring for Terbinafine

• Perform baseline liver function tests before prescribing - hepatotoxicity can occur in patients with or without pre-existing liver disease 6
• Monitor for hepatotoxicity symptoms: persistent nausea, anorexia, fatigue, vomiting, right upper abdominal pain, jaundice, dark urine, or pale stools 6
• Discontinue immediately if liver function tests elevate or hepatotoxicity symptoms develop 6
• Warn patients about taste and smell disturbances - can be severe, prolonged (>1 year), or permanent 6

What Dermatophytes Do NOT Treat

Griseofulvin and terbinafine are not effective for:

• Bacterial infections, Candidiasis, Histoplasmosis, Sporotrichosis, Tinea versicolor, or other non-dermatophyte fungal infections 5