What is the best approach to manage a female patient presenting with dermatitis on the chin and lower half of the face, which began after exposure to questionable water while bathing in it during a trip, and has persisted since then?

Management of Persistent Facial Dermatitis Following Water Exposure

This patient most likely has irritant contact dermatitis from contaminated water exposure, and should be managed with strict avoidance of irritants, gentle skin care with soap-free cleansers, liberal emollients, and topical hydrocortisone cream applied 3-4 times daily to affected areas. 1

Differential Diagnoses to Consider

The clinical presentation of persistent lower facial dermatitis following water exposure suggests several possibilities:

• Irritant Contact Dermatitis (most likely): Water itself is an irritant, and contaminated water containing chemicals, microorganisms, or other substances can cause persistent irritant dermatitis 1
• Allergic Contact Dermatitis: Delayed hypersensitivity to substances in the water (chemicals, preservatives, metals) 1, 2
• Infectious Dermatitis: Bacterial superinfection (particularly Staphylococcus aureus) complicating the initial irritant reaction 3
• Perioral Dermatitis: Can be triggered by irritants and presents with lower facial involvement 4
• Parasitic/Helminthic Infection: Given the travel history and questionable water exposure, consider cercarial dermatitis or other water-borne parasitic causes, though these typically present acutely 1

Initial Management Approach

Immediate Skin Care Measures

Avoidance is the cornerstone of treatment for both irritant and allergic contact dermatitis. 1

• Eliminate all potential irritants: Avoid soaps, detergents, and harsh cleansers on the face 1
• Use pH-neutral synthetic detergents or soap-free cleansers rather than traditional soap, which can further irritate compromised skin 1
• Pat dry gently with soft, clean towels rather than rubbing 1
• Avoid perfumes, alcohol-based lotions, and other skin irritants 1

Topical Treatment

Apply topical hydrocortisone 1% cream to affected areas 3-4 times daily as first-line anti-inflammatory treatment. 5, 6 This is FDA-approved for inflammation, itching, and rashes in adults and children over 2 years. 5

• Liberal use of emollients: Apply urea- or glycerin-based moisturizers frequently to restore the skin barrier 1, 6
• Avoid greasy topical products as they can promote superinfection 1
• For inflammatory lesions, hydrocortisone cream is appropriate for facial use given its lower potency and reduced risk of complications compared to more potent corticosteroids 1, 4

Important caveat: Chronic, uninterrupted application of even 1% hydrocortisone on the face can cause perioral dermatitis, rosacea-like eruptions, and eyelid atrophy/telangiectasia. 4 Therefore, treatment should be intermittent once improvement occurs, not continuous.

Diagnostic Evaluation

Patch testing should be strongly considered given the persistent nature of the dermatitis and clear temporal relationship to water exposure. 1, 2

Indications for patch testing in this patient include:

• Disease aggravated by specific exposure (contaminated water) 1
• Persistent/recalcitrant disease not responding to standard treatments 1
• Unusual distribution or timing of onset 1

Bacterial culture from the affected area should be obtained if there are signs of secondary infection (crusting, weeping, pustules) to guide antibiotic therapy if needed. 3

When to Escalate Treatment

Reassess after 2 weeks. 1

If worsening or no improvement:

• Consider combined antibiotic/corticosteroid cream if bacterial superinfection is suspected (though be aware this increases risk of antibiotic resistance) 3
• Consider topical calcineurin inhibitors (pimecrolimus or tacrolimus) as steroid-sparing agents for facial dermatitis 6
• Refer to dermatology for patch testing to identify specific allergens 1, 2
• Consider oral antibiotics if significant bacterial infection is present 1, 3

Travel-Related Considerations

Given the travel history and water exposure, consider:

• Parasitic causes are unlikely if there is no eosinophilia, but check a complete blood count 1
• Katayama syndrome (acute schistosomiasis) typically presents 2-9 weeks after freshwater exposure with fever, urticarial rash, and eosinophilia—not isolated persistent facial dermatitis 1
• Most water-borne dermatologic conditions present acutely, not as chronic persistent dermatitis 1

Common Pitfalls to Avoid

• Do not use potent topical steroids on the face without dermatology consultation, as this significantly increases risk of perioral dermatitis, rosacea, and skin atrophy 4
• Do not continue hydrocortisone indefinitely—once improvement occurs, transition to intermittent use and maintenance with emollients alone 4, 6
• Do not empirically treat with antibiotics without evidence of bacterial infection, as this promotes resistance 3
• Do not dismiss the need for patch testing in persistent cases—allergic contact dermatitis requires specific allergen identification and avoidance for resolution 1, 2