How should I manage a cut and contact dermatitis from stinging nettle (Urtica dioica)?

Management of Stinging Nettle Contact

For stinging nettle exposure causing both a cut and contact dermatitis, immediately wash the area with soap and water, apply cold compresses, and use an oral antihistamine like cetirizine for the urticarial reaction; treat the cut with standard wound care and apply topical hydrocortisone 1% cream to the surrounding dermatitis 3-4 times daily.

Immediate First Aid Measures

Wound Care for the Cut

• Clean the cut thoroughly with mild soap and warm water to remove any plant material and reduce infection risk 1
• Pat dry gently rather than rubbing, as friction may spread the irritant substances 1
• Apply standard wound care principles: keep clean, dry, and covered if needed 2

Addressing the Contact Reaction

• Apply cold compresses immediately to the affected area to reduce pain, swelling, and the stinging sensation 3, 4
• The stinging nettle releases histamine (approximately 6.1 ng per hair), serotonin, and other biologically active substances that cause immediate urticaria and dermatitis 5, 6
• The reaction typically causes itching, burning, and urticaria within moments of contact, with stinging sensations that can persist for more than 12 hours 5, 6

Pharmacologic Treatment

Oral Antihistamines (First-Line)

• Start cetirizine immediately as it reaches peak plasma concentration fastest and provides rapid relief for the urticarial component 3
• Alternative second-generation antihistamines include fexofenadine, loratadine, desloratadine, or levocetirizine 3
• These address the histamine-mediated itching and urticaria that characterize nettle exposure 3, 5
• If standard dosing provides inadequate control, the dose may be increased up to four times the usual amount 3

Topical Corticosteroids

• Apply hydrocortisone 1% cream to the affected area 3-4 times daily for the contact dermatitis component 7
• For more severe reactions with extensive erythema and swelling, mid- to high-potency topical steroids such as triamcinolone 0.1% or clobetasol 0.05% may be used 2
• Topical corticosteroids combined with emollients are widely accepted as standard treatment for established contact dermatitis 1

Adjunctive Symptomatic Measures

• Apply cooling antipruritic lotions such as calamine or 1% menthol in aqueous cream to reduce itching 3
• Use oral analgesics if pain is significant 3, 4
• Soap substitutes and emollients help restore the skin barrier 1

When to Escalate Treatment

Short-Course Oral Corticosteroids

• If the reaction involves extensive swelling (a large local reaction), consider a brief oral corticosteroid course such as prednisolone 50 mg daily for 3 days in adults 3, 4
• The swelling in the first 24-48 hours is due to allergic inflammation, not infection, so antibiotics are unnecessary 3, 4
• Never use corticosteroids as maintenance therapy—only for short-term control during acute reactions 3

Systemic Steroids for Extensive Involvement

• If allergic contact dermatitis involves more than 20% of body surface area, systemic steroid therapy may be required and typically provides relief within 12-24 hours 2
• For severe cases, oral prednisone should be tapered over 2-3 weeks to prevent rebound dermatitis 2

Critical Pitfalls to Avoid

• Do not prescribe antibiotics unless there is clear evidence of secondary infection (purulence, spreading erythema beyond 48 hours, fever)—the initial swelling is from mediator release, not infection 3, 4
• Do not use epinephrine for isolated cutaneous reactions; it is indicated only for systemic anaphylaxis with respiratory symptoms, hypotension, or throat swelling 3
• Do not rely on first-generation sedating antihistamines as monotherapy, though they may be added at bedtime if needed 3
• Avoid applying topical corticosteroids to open wounds; use only on intact skin around the cut 7

Expected Course and Follow-Up

• The immediate urticarial reaction is self-limited and typically resolves within hours to days with symptomatic treatment 5
• The stinging sensation may persist for 12+ hours due to direct nerve toxicity or secondary mediator release 6
• Mast cell degranulation occurs within 5 minutes and can persist for 12 hours, explaining the prolonged symptoms 6
• There is no standard treatment protocol for stinging nettle dermatitis, so management is symptomatic and supportive 5

Special Considerations

• Pregnancy: Use cetirizine or loratadine (FDA Category B) as preferred antihistamines; avoid hydroxyzine in early pregnancy 3
• Renal impairment: Reduce cetirizine and levocetirizine doses by 50% 3
• Children under 2 years: Consult a physician before applying topical hydrocortisone 7
• For children 2 years and older, hydrocortisone 1% may be applied 3-4 times daily 7