Gypsum Plaster Allergy: Recognition, Symptoms, and Management

Gypsum plaster (calcium sulfate dihydrate) is generally inert and non-toxic. True IgE-mediated allergy is extremely rare. Most reactions are irritant contact dermatitis or respiratory irritation from dust.

Clinical Presentations

• Skin: Erythema, dryness, pruritus, fissuring on exposed areas (hands, forearms, face). Irritant, not allergic.
• Respiratory: Cough, sneezing, throat irritation, dyspnea, wheezing (especially in asthmatics) from alkaline dust (pH ~12 when wet).
• Ocular: Conjunctival injection, tearing, foreign-body sensation from dust.
• Systemic (anaphylaxis): Vanishingly rare; case reports only. Would present with angioedema, bronchospasm, hypotension.

Diagnosis

• History of exposure–symptom correlation.
• Patch testing (if allergic contact dermatitis suspected): gypsum 20% pet. – usually negative.
• Specific IgE to gypsum: not commercially available; not indicated.

Management

• Prevention: N95 respirator, goggles, gloves, long sleeves, ventilation, wet-sanding.
• Skin: Barrier creams, prompt washing, topical corticosteroids for dermatitis.
• Respiratory: Remove from exposure; bronchodilators/inhaled steroids if asthma exacerbation.
• Ocular: Irrigation, artificial tears.

Key Distinction

Irritation ≠ Allergy. Most “gypsum allergy” labels reflect irritant effects. True allergy warrants allergist evaluation but is exceptionally uncommon.