Erythroderma (Exfoliative Dermatitis)

Erythroderma is a rare, severe, medical emergency involving generalized inflammation and scaling affecting >90% of the body surface area. Patients often report a preceding dermatitis flare, a recent drug exposure, or withdrawal of a long-term topical/systemic medication.

Common Triggers:

• Drug Reactions: Antibiotics, anticonvulsants (e.g., phenytoin), or allopurinol (onset often 2–5 weeks after starting).

• Underlying Skin Diseases: Severe flares of Psoriasis, Atopic Dermatitis, or Contact Dermatitis.

• Malignancy: Cutaneous T-cell Lymphoma (CTCL) like Sézary syndrome.

• Withdrawal: Sudden stopping of systemic steroids or immunosuppressants.

Symptoms:

• Widespread skin discoloration or redness that is progressively worsening.

• Severe, often intolerable itch.

• Systemic distress: Malaise, fatigue, chills, or feeling cold (due to heat loss).

• May report fever or lymphadenopathy.

Crucial Note for Darker Skin Tones:

Patients rarely describe "redness." Instead, they report generalized darkening, a violet/violaceous tone, or a widespread hyperpigmentation. This difference is vital to recognize so the diagnosis is not missed.

Skin Findings (>90% involvement):

• • • Colour: Generalized erythema in lighter skin; brown, violaceous, or hyperpigmented hue in darker skin types.

    • Texture: Warm, oedematous (swollen) skin. Fine or sheet-like scale develops 2–6 days after the color change begins.

    • Associated Changes: Diffuse hair shedding (alopecia) and characteristic nail changes (ridging, thickening, shedding).

    • Lymphadenopathy is common and may suggest drug hypersensitivity or lymphoma.

Systemic Findings (Life-Threatening Complications):

Due to massive epidermal turnover and barrier loss:

• • • Thermoregulation: Hypothermia (inability to retain heat).

    • Fluid/Electrolytes: Dehydration and peripheral oedema (swelling).

    • Cardiac: Potential for signs of high-output cardiac failure due to increased blood flow to the skin.

Key Clues to Underlying Cause:

• • • Psoriasis: Persistent, thicker plaques or keratoderma on palms/soles.

    • Atopic Dermatitis: Widespread ooze, crusting, and intense itch.

    • Sézary Syndrome: Severe itch, erythroderma, and generalized lymphadenopathy.

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Erythroderma is a medical emergency requiring hospitalization for monitoring and supportive care.

1. General Supportive Measures (Critical):

• Discontinue Drugs: Immediately stop all non-essential medications to eliminate a drug trigger.

• Monitoring: Close monitoring of vital signs, fluid/electrolyte balance, and temperature.

• Skin Barrier Maintenance: Use wet wraps/cool compresses followed by liberal application of thick emollients (ointment-based). Mild topical steroids may be used for acute inflammation.

• Complications: Treat secondary bacterial infection promptly with systemic antibiotics. Provide nutritional support due to high metabolic demand.

2. Treating the Underlying Cause:

• Psoriasis: Systemic agents like Acitretin, Methotrexate, or Cyclosporin (avoid sudden steroid withdrawal).

• Atopic Dermatitis: Systemic steroids (short course) or immunosuppressants.

• Drug-Induced: Immediate withdrawal of the drug, supportive care, $\pm$ short-course systemic steroids depending on severity.

• Malignancy: Requires referral to Dermatology/Haematology for specialized therapies.

Darker Skin Tones – Treatment Considerations:

• Counselling: Counsel patients early that pigment changes (hyper- and hypopigmentation) are common and may be severe and persist for months to years after recovery.

DermNet NZ – “Erythroderma” (Author: Vanessa Ngan; updated 2016): https://dermnetnz.org/topics/erythroderma

DynaMed – “Erythroderma in Adults” (Background Information): https://www.dynamed.com/condition/erythroderma-in-adults#GUID-82407742-7CC9-4B2A-9DA6-B989CF