What are the red flags for dermatitis?

Red Flags for Dermatitis

The most critical red flags requiring urgent intervention are eczema herpeticum (widespread punched-out erosions with systemic symptoms), severe cutaneous adverse reactions (SCARs) including Stevens-Johnson syndrome/toxic epidermal necrolysis, and signs of systemic bacterial infection with sepsis. 1

Life-Threatening Emergencies

Eczema Herpeticum

• Multiple uniform "punched-out" erosions or vesicles that develop rapidly, representing herpes simplex virus superinfection 1, 2
• Fever, malaise, and lymphadenopathy accompanying skin lesions 1, 3
• This is a dermatologic urgency requiring immediate systemic antiviral therapy (acyclovir) due to increased morbidity and potential mortality 1, 2
• Can be life-threatening, particularly in patients with atopic dermatitis 3

Severe Cutaneous Adverse Reactions (SCARs)

• Fever with widespread rash that is painful rather than just pruritic 1
• Skin sloughing, blistering, or erosions affecting large body surface areas 1
• Facial or upper-extremity edema with pustules 1
• Mucosal involvement (oral, ocular, genital erosions) 1
• These presentations suggest Stevens-Johnson syndrome, toxic epidermal necrolysis, or drug reaction with eosinophilia and systemic symptoms (DRESS) 1

Serious Bacterial Superinfection

Frank Bacterial Infection Requiring Systemic Antibiotics

• Purulent exudate and pustules on examination, distinguishing infection from simple inflammation 1
• Honey-colored crusting with weeping discharge 2, 4
• Rapidly spreading erythema with warmth and tenderness 1, 5
• Systemic signs including fever, chills, or malaise suggesting bacteremia 5
• While Staphylococcus aureus colonization occurs in >90% of atopic dermatitis patients, only frank infection with these clinical signs warrants systemic antibiotics 1, 5

Warning Signs of Severe or Refractory Disease

Indicators of Complicated Dermatitis

• Widespread involvement affecting large body surface areas despite appropriate topical therapy 4, 6
• Severe pruritus causing sleep disturbance and significantly impaired quality of life 4, 6
• Failure to respond to first-line topical corticosteroids and emollients after 1-2 weeks 2, 4
• Chronic lichenification with hyperpigmentation indicating prolonged uncontrolled disease 3

Occupational Contact Dermatitis Red Flags

• Symptoms that improve away from work (weekends, holidays) and recur upon return 1
• Progressive worsening despite attempted avoidance measures 1, 7
• Poor prognosis indicators: only 25% of occupational contact dermatitis patients achieve complete recovery within 10 years, with 25% having permanent symptoms 7

Diagnostic Red Flags

When to Suspect Allergic Contact Dermatitis

• Recalcitrant dermatitis not responding to standard irritant avoidance and emollients 1, 8
• Pattern suggesting specific allergen exposure (e.g., jewelry distribution for nickel, facial involvement with cosmetics) 1, 8
• Worse prognosis than irritant dermatitis unless allergen identified and avoided 8
• Requires patch testing for definitive diagnosis, as clinical features alone are unreliable 1, 8

Atypical Presentations Requiring Further Investigation

• Dermatitis in diaper area of infants (rarely atopic dermatitis) 3
• Unilateral or highly localized plaques not responding to standard therapy 2
• Symptoms worsening after sunlight exposure suggesting photoallergic or phototoxic dermatitis 1, 8

Common Pitfalls to Avoid

• Do not assume all crusting represents infection – crusting can occur in active dermatitis without bacterial superinfection 1
• Avoid prolonged systemic antibiotics for colonization alone without frank infection signs, as this promotes resistance without improving dermatitis outcomes 1
• Do not rely on morphology alone to distinguish allergic from irritant contact dermatitis – patch testing is essential when allergic etiology suspected 1, 8
• Recognize that oral antihistamines do not reduce pruritus in atopic dermatitis and should not be routinely recommended 4