# Acute allergic angioedema - Category: chronic - Review status: reviewed (every claim checked against a document named on this page) - Sources: Resuscitation Council UK Anaphylaxis Guideline 2021 · Egyptian National Drug Formulary - Respiratory System 2026 (cetirizine monograph) - Verified date: 2026-08 ## Verified against - Resuscitation Council UK Anaphylaxis Guideline 2021 - Egyptian National Drug Formulary - Respiratory System 2026 (cetirizine monograph) - Acute allergic angioedema - disease-level clinical article (angioedema-clinical.txt) ## Treatment metadata - Adrenaline — 1 mg — injection - Referral & safety-netting (no drug therapy) - Cetirizine — 10 mg — oral.solid - Hydrocortisone — 100 mg — injection ## Complete treatment card ```text ACUTE ALLERGIC ANGIOEDEMA Sources: Resuscitation Council UK Anaphylaxis Guideline 2021 · Egyptian National Drug Formulary - Respiratory System 2026 (cetirizine monograph) Review status: REVIEWED against Resuscitation Council UK Anaphylaxis Guideline 2021, Egyptian National Drug Formulary - Respiratory System 2026 (cetirizine monograph), Acute allergic angioedema - disease-level clinical article (angioedema-clinical.txt) (2026-08) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (8) - Histaminergic angioedema can involve skin swelling, redness, and itching, breathing symptoms like bronchospasm, and abdominal pain with vomiting [abdominal pain · itching · redness · vomiting] - Histaminergic swelling starts within an hour of exposure and can last one to two days - Bradykinin-mediated swelling is not accompanied by hives, and lasts longer and is more severe than histaminergic swelling, with abdominal symptoms - ACE-inhibitor-related angioedema presents without hives or itching - NSAID-induced angioedema can present with hives and facial swelling [facial swelling · urticaria] - Hereditary angioedema starts in childhood or young adulthood and worsens at puberty, with recurrent swelling or abdominal pain [abdominal pain] - A serpiginous, non-itchy rash called erythema marginatum can be a warning sign before a hereditary angioedema attack [rash · redness] - A hereditary angioedema attack peaks over about a day and settles within two to three days SIGNS - what you find (1) - A full exam should check vital signs, mental status, and the skin, head, neck, airway, and abdomen TESTS (6) - C4 and tryptase blood tests, drawn during an acute attack, screen for hereditary angioedema and anaphylaxis-related angioedema respectively - Tryptase stays normal in hereditary angioedema types 1 and 2 but rises with anaphylaxis or other mast-cell disorders - Flexible fiberoptic laryngoscopy can check tongue and larynx involvement when there are upper- airway symptoms - Hereditary angioedema type 1 shows low C1-inhibitor function, low C1-inhibitor level, and low C4 - Hereditary angioedema type 2 shows low C1-inhibitor function and low C4 but a normal or high C1-inhibitor level - Acquired C1-inhibitor deficiency shows low C1-inhibitor antigen and function along with low C1q IF NOT THIS - what else fits (12) - Acute contact dermatitis is a differential to rule out - Drug rash with eosinophilia and systemic symptoms, or DRESS, can mimic it - Dermatomyositis belongs on the differential - Morbus Morbihan, chronic facial swelling linked to rosacea, is a differential - Superior vena cava syndrome can cause facial swelling mistaken for angioedema - Hypothyroidism-related myxedema is on the differential - Subcutaneous emphysema is a differential for swelling - Orofacial granulomatosis is a differential to consider - Hypocomplementemic urticarial vasculitis syndrome is on the differential - Clarkson's disease, or systemic capillary leak syndrome, is a differential - Gleich's syndrome, episodic angioedema with eosinophilia, is a differential - Hereditary angioedema can be mistaken for familial Mediterranean fever Source StatPearls "Angioedema" - disease-level clinical article Status traced to the source above !! MULTI-DRUG REGIMEN - all 2 drugs are given TOGETHER. Not a choice between them. !! the regimen: Cetirizine + Hydrocortisone 1. ADRENALINE [1st line] Adult 0.5 mg IM (0.5 mL of 1:1000 / 1 mg/mL) into anterolateral mid-thigh; repeat after 5 minutes if airway involvement or hypotension persists - single dose Peds Child: 0.01 mg/kg (0.01 mL/kg of 1:1000) IM into outer thigh (child <6y: 0.15 mg; 6-12y: 0.3 mg; >12y: 0.5 mg) Source Resuscitation Council UK Anaphylaxis Guideline 2021 Why First-line life-saving treatment for acute allergic angioedema with airway compromise or anaphylaxis Caution MUST be given intramuscularly (IM) into mid-outer thigh, NOT intravenously (IV injection carries fatal cardiac arrhythmia risk). Call emergency services immediately for hospital transport. Transient pallor, tremor, palpitations, and anxiety are expected pharmacological effects. Egypt EPINEPHRINE-MEMPHIS 1 MG/ML 5 I.M./S.C. AMP. MEMPHIS 10.00 EGP ADRENAMAX 1 MG/1ML 10 AMPS. CHEMIPHARM 75.00 EGP EPINEPHRINE-MISR 1 MG/ML 100 AMP. MISR 750.00 EGP ADRENALINE-CID 1 MG/1ML 100 I.M./S.C. AMP. CID 850.00 EGP 2. REFERRAL & SAFETY-NETTING (NO DRUG THERAPY) [1st line] Adult Source Angioedema - disease-level clinical article (angioedema-clinical.txt) Why Carries the referral criteria and warning signs for this condition, which apply whichever treatment is chosen. Caution RED FLAG - Laryngeal/airway involvement makes angioedema life-threatening. Airway compromise needs urgent airway management and hospital referral (intubation or surgical airway), not simply a repeat adrenaline dose at 5 minutes. RED FLAG - If the episode does not respond to epinephrine, an antihistamine and a corticosteroid, that itself is a red flag for bradykinin-mediated angioedema (e.g. ACE- inhibitor-induced or hereditary), which needs a different approach: stop the ACE inhibitor and never rechallenge, and refer for bradykinin-targeted therapy. 3. CETIRIZINE [1 of 2 - GIVE ALL TOGETHER] Adult 10 mg once daily oral (or chlorphenamine 10 mg slow IV/IM in emergency setting) x 3-5 days Peds 2 to under 6 years: 2.5 mg twice daily 6 to under 12 years: 5 mg twice daily 12 years and over: 10 mg once daily (Child 2-5 years: 2.5 mg twice daily; 6-11 years: 5 mg twice daily; >=12 years: 10 mg once daily) Source Egyptian National Drug Formulary - Respiratory System 2026 (cetirizine monograph) Why Secondary adjunctive therapy after adrenaline Caution Antihistamines DO NOT treat or prevent laryngeal edema or anaphylactic shock; adrenaline must be given first. Egypt EPIRIZINE 10 MG 10 TABS. EIPICO 15.50 EGP (1.55/unit) CETRITIN 10MG 20 TAB. EL NILE. 42.00 EGP (2.10/unit) TOMAZINE 10MG 30 F.C. TABS. ALFACURE PHAR... 63.00 EGP (2.10/unit) CETRAK 10 MG 20 TABS. PHARCO 68.00 EGP (3.40/unit) HISTAZINE-1 10 MG 20 TABS. AMRIYA 68.00 EGP (3.40/unit) ZYRTEC 10 MG 20 TAB. GLAXO SMITHKLINE 100.00 EGP (5.00/unit) CETRICHEW 10MG 20 CHEWABLE F.C. TABS. AL ROWAD PHARMACEUTICAL INDUSTRIAL... 15.00 EGP HISTA CHEW 10 MG 20 CHEWABLE TAB. ARAB CAPS > ADVOCURE 15.00 EGP LERGFREE 5MG/5ML SYRUP 120ML DEBEIKY 9.00 EGP -> ? strength differs, ? different route - not oral solid EPIRIZINE 5MG/ML SYRUP 60 ML EIPICO 19.00 EGP -> ? strength differs, ? different route - not oral solid 4. HYDROCORTISONE [2 of 2 - GIVE ALL TOGETHER] Adult 200 mg slow IV or IM (or Prednisolone 40-50 mg orally) - single dose Peds Child: 2-4 mg/kg IV/IM (max 100 mg for <6 yrs, 200 mg for >=6 yrs) Source Resuscitation Council UK Anaphylaxis Guideline 2021 Why Adjunctive therapy to prevent biphasic late-phase allergic reaction Caution Delayed onset of action (4-6 hours); never rely on corticosteroids for immediate airway relief. Egypt SOLU-CORTEF 100MG/2ML VIAL EIPICO > PFIZER 16.00 EGP HYDROCORTISONE SODIUM SUCCINATE 100MG I.V./I.M.VIAL EIPICO 26.00 EGP Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy. ``` --- Dawaa Reference is a reference for prescribers, not a medical device, and does not replace clinical judgement. [Privacy policy](/privacy)