Medical Diagnosis for Intermittent Hives
The medical diagnosis for intermittent hives is "episodic urticaria" (also termed "acute intermittent urticaria" or "recurrent acute urticaria"), characterized by spontaneous weals that appear and resolve in discrete episodes rather than occurring continuously every day. 1
Classification Framework
Urticaria is classified by temporal pattern rather than etiology, because the underlying cause often remains elusive even after thorough evaluation. 1 The key diagnostic categories based on duration and pattern are:
- Acute urticaria: Continuous activity lasting up to 6 weeks 1
- Episodic (intermittent) urticaria: Acute intermittent or recurrent activity with symptom-free intervals 1
- Chronic urticaria: Continuous or near-daily activity for 6 weeks or more 1
Your presentation of intermittent hives—with discrete episodes separated by symptom-free periods—fits the episodic urticaria pattern. 1 This differs from chronic urticaria, where weals occur continuously every day or almost daily while the disease is active. 1
Diagnostic Criteria
The diagnosis is primarily clinical and does not require laboratory testing unless the history suggests a specific trigger. 2 Key diagnostic features include:
- Individual wheals lasting 2–24 hours before resolving without scarring 1, 2
- Pruritus (itching) as the predominant symptom 1
- Migratory pattern with new lesions appearing as old ones fade 2
- Spontaneous appearance without reproducible physical triggers 1
If individual wheals persist beyond 24 hours, leave bruising or hyperpigmentation, or are painful rather than itchy, urticarial vasculitis must be excluded with a lesional skin biopsy. 2, 3
Common Etiologies in Episodic Urticaria
Although many cases remain idiopathic, identifiable triggers in episodic urticaria include: 1, 4
- IgE-mediated food allergies (nuts, shellfish, eggs, milk) 2, 4, 5
- Medications causing direct mast cell degranulation (NSAIDs, aspirin, opioids, radiocontrast media) 4
- Infections (viral upper respiratory infections are common in acute/episodic presentations) 6, 7
- Contact allergens (latex, chemicals) 1, 2
Routine extensive laboratory work-up is unnecessary for typical episodic urticaria that responds to antihistamines. 2, 3 Testing should be guided by history: if a specific food allergy is suspected, skin-prick testing or specific IgE assays can confirm sensitization. 2, 3
Risk of Chronicity
Approximately 25% of patients presenting with first-attack acute urticaria will progress to chronic urticaria. 7 Positive anti-thyroid peroxidase (anti-TPO) antibodies increase the risk of chronicity 1.69-fold, so testing anti-TPO at initial presentation may help predict disease course. 7 Patients with recurrent episodic attacks (multiple discrete episodes over time) have a higher likelihood of eventual chronicity. 7
Critical Red Flags Requiring Immediate Evaluation
- Laryngeal angioedema (throat tightness, hoarseness, dysphagia) or anaphylaxis mandates immediate intramuscular epinephrine. 2
- Angioedema without wheals requires urgent screening for C1-esterase inhibitor deficiency (measure serum C4) or ACE-inhibitor-induced angioedema, because these conditions do not respond to antihistamines or corticosteroids. 1, 2
- Wheals persisting >24 hours with pain or burning sensation suggest urticarial vasculitis and require skin biopsy. 2, 3
Common Pitfalls to Avoid
- Do not perform extensive laboratory panels (CBC, ESR, CRP, complement levels, thyroid function) in straightforward episodic urticaria with good antihistamine response; these tests are reserved for chronic urticaria or when systemic disease is suspected. 2, 3
- Do not confuse episodic urticaria with physical urticarias, which are triggered reproducibly by specific stimuli (pressure, cold, heat, exercise) and resolve within 1 hour of the trigger. 1, 2
- Avoid long-term oral corticosteroids; short courses (lower than 50 mg daily for 3 days in adults) may shorten acute episodes, but prolonged use is inappropriate. 2