# Diphtheria - Category: chronic - Review status: reviewed (every claim checked against a document named on this page) - Sources: Diphtheria - StatPearls (NCBI Bookshelf NBK560911) - https://www.ncbi.nlm.nih.gov/books/NBK560911/ · ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class RD10.00 - condition scope only, no dose · Diphtheria - disease-level clinical article (diphtheria-clinical.txt) · UK eMC Phenoxymethylpenicillin 250 mg Film-coated Tablets SmPC - Verified date: 2026-09 ## Verified against - Diphtheria - disease-level clinical article (diphtheria-clinical.txt) - UK eMC Phenoxymethylpenicillin 250 mg Film-coated Tablets SmPC ## Treatment metadata - Referral & safety-netting (no drug therapy) - Diphtheria antitoxin — injection - Penicillin G — injection - Phenoxymethyl penicillin — oral.solid - Erythromycin — oral.solid ## Complete treatment card ```text DIPHTHERIA Sources: Diphtheria - StatPearls (NCBI Bookshelf NBK560911) - https://www.ncbi.nlm.nih.gov/books/NBK560911/ · ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class RD10.00 - condition scope only, no dose · Diphtheria - disease-level clinical article (diphtheria-clinical.txt) · UK eMC Phenoxymethylpenicillin 250 mg Film-coated Tablets SmPC Review status: REVIEWED against 2 sources listed above (2026-09) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (4) - The incubation period runs about 2 to 5 days, ranging up to 10 days - Respiratory disease starts with mild throat redness that progresses to a thick, adherent membrane [redness] - Low-grade fever, sore throat, malaise, neck node swelling, and headache are common [fever · headache · lymphadenopathy · malaise · sore throat] - Skin disease presents as chronic, nonhealing ulcers covered by a gray membrane, often at a site of prior injury SIGNS - what you find (9) - The patient looks toxic with low-grade fever and a swollen neck [fever] - Fever, a fast heart rate, bad breath, and anxiety are general findings [anxiety · fever · tachycardia] - A thick gray coating spreads over the throat, nose, and mouth structures and bleeds if scraped away [bleeding] - The bull-neck appearance comes from marked neck node swelling and soft-tissue edema [lymphadenopathy · oedema] - Airway obstruction from an extensive membrane is a leading cause of death - The patient may hold the head extended because of the bull neck, with occasional voice change [hoarseness] - Respiratory distress shows as stridor, wheeze, cyanosis, and retractions [breathlessness · chest recession · cyanosis · stridor · wheeze] - Myocarditis can present acutely with heart failure and circulatory collapse, or more subtly with progressive breathlessness and dilated cardiac chambers [breathlessness · shock] - Neurological involvement can include cranial nerve deficits and a stocking-glove sensory neuropathy TESTS (7) - Cardiac evaluation for suspected myocarditis includes ECG, troponin, and echocardiography - ECG changes can include ST-segment and T-wave changes, AV blocks, and dysrhythmias - Culture of the infected site should be taken before antibiotics are started when possible - Isolated bacilli need toxigenicity testing - a positive tox gene by PCR still requires confirmation of actual toxin production - A complete blood count may show leukocytosis, a nonspecific finding - Chest x-ray can be used to look for pneumonia or aspiration, and neck imaging for airway compromise - Antitoxin serology reflects immune status but is not used to diagnose acute infection IF NOT THIS - what else fits (7) - Epiglottitis, marked by sudden swelling of the epiglottis and nearby tissue, is a differential - Retropharyngeal abscess presents with high-grade fever and needs urgent drainage - Angioedema presents as generalized swelling of the lower dermis and subcutaneous or submucosal tissue - Infectious mononucleosis can look similar, with tiredness, malaise, throat pain, fever, nausea, loss of appetite, and cough - classically with fever, pharyngitis, and swollen nodes in a child - Pharyngitis shows sudden-onset sore throat, painful swallowing, fever, and cough - Oral candidiasis has a whitish pseudomembrane, distinguishing it from diphtheria's grayish one - Vincent angina involves gum infection with painful, bleeding gums and ulcerative gingival necrosis Source StatPearls "Diphtheria" - disease-level clinical article Status traced to the source above Rx: Main treatment | Toxin neutralisation | Antibiotic | Antibiotic - oral switch | Antibiotic - alternative MAIN TREATMENT 1. REFERRAL & SAFETY-NETTING (NO DRUG THERAPY) [1st line] Adult A toxin-mediated bacterial throat infection causing a pseudomembrane with risk of airway obstruction and myocarditis; rare in Egypt due to EPI vaccination coverage, but any suspected case needs immediate hospital referral for antitoxin and antibiotic treatment plus public health notification, since delay is dangerous. - Refer, with advice Peds Children follow the same urgent pathway. The antibiotic is dosed by weight band and the antitoxin by clinical state, not per kilogram. Source No dose - referral pathway, no medicine given in primary care Why A toxin-mediated bacterial throat infection causing a pseudomembrane with risk of airway obstruction and myocarditis; rare in Egypt due to EPI vaccination coverage, but any suspected case needs immediate hospital referral for antitoxin and antibiotic treatment plus public health notification, since delay is dangerous. Caution Rare in Egyptian primary care. A notifiable public-health emergency: notify, isolate with droplet precautions, and refer the same day. The antitoxin and antibiotics below are what the receiving service gives, set out so the pathway is clear - they are not a reason to treat in the surgery and delay the referral. RED FLAG - Stridor or difficulty breathing means impending airway obstruction and is an emergency. A grey pseudomembrane on the tonsils or pharynx, or signs of myocarditis such as an irregular heartbeat or heart failure or of neuropathy, indicate complications: refer immediately. TOXIN NEUTRALISATION 2. DIPHTHERIA ANTITOXIN [1st line] Adult Dose is set by the patient's clinical state and the severity of disease, not by weight; given intramuscularly or intravenously - single course Peds Same urgent pathway. The dose is set by clinical state and severity rather than by weight. Source Diphtheria - disease-level clinical article (diphtheria-clinical.txt) Why The article makes antitoxin the primary treatment alongside antibiotics, and says to give it urgently on clinical judgement without waiting for laboratory confirmation. Caution RED FLAG - Give urgently on clinical suspicion. The antitoxin neutralises only unbound toxin and is ineffective once the toxin has bound to the cell membrane. Derived from horse antiserum. Hypersensitivity testing before administration, with drugs for anaphylaxis ready at the bedside. Notify the public health authority and isolate the patient with droplet precautions at the same time. Egypt DIPHTHERIA ANTITOXIN 10000I.U. 10ML VIAL VACSERA 413.00 EGP ANTIBIOTIC 3. PENICILLIN G [1st line] Adult 600,000 units intramuscularly every 12 hours for a patient over 10 kg; switch to oral penicillin V once oral medication is tolerated x 14 days in total, counting the oral switch Peds By weight band, not per kilogram: 300,000 units intramuscularly every 12 hours at 10 kg or less; 600,000 units every 12 hours over 10 kg. Source Diphtheria - disease-level clinical article (diphtheria-clinical.txt) Why The article names erythromycin or penicillin G the antibiotics of choice. In Egypt penicillin G is the one that is stocked. Caution Start antibiotics early to clear the organism, limit toxin release and stop spread to close contacts. Take cultures before starting antibiotics where that is feasible. If the organism is resistant, the article names linezolid or vancomycin as the alternatives. Post-exposure prophylaxis for close contacts and for staff exposed to respiratory secretions: a single intramuscular dose of penicillin G, 600,000 units under 6 years and 1.2 million units at 6 years and over; or oral erythromycin 500 mg four times daily for 7 to 10 days. Egypt AQUA-PEN 1 M.I.U. VIAL. MISR > CID 7.50 EGP BENZYL PENICILLIN 1 M.I.U. B.P2004 VIAL. MISR 15.00 EGP ANTIBIOTIC - ORAL SWITCH 4. PHENOXYMETHYL PENICILLIN [1st line] Adult 250 mg four times daily x 2 weeks, the same course the injection started Peds Specialist paediatric infectious-disease dosing. Source Diphtheria - disease-level clinical article (diphtheria-clinical.txt) Why The article's oral step-down once the patient can take oral medication, completing the two-week course. It calls the drug penicillin V; the Egyptian register spells it phenoxymethyl penicillin, which is the same medicine. Caution No tablet on the Egyptian market delivers this dose whole. 250 mg is about 400,000 units (UK SmPC, Phenoxymethylpenicillin 250 mg tablets), so the marketed OSPEN 1.0 MIU and 1.5 MIU tablets are roughly 625 mg and 940 mg. The receiving service sets the practical dose. Toxigenic strains are considered non-contagious only after at least 48 hours of appropriate antibiotics. Confirm eradication with two consecutive negative cultures taken at least 24 hours apart after the course finishes. Egypt stocks the tablet only: OSPEN 1.0 and 1.5 MIU are marketed, and the 400,000 IU/5 mL suspension carries the (N/A) withdrawn marker, so there is no oral liquid on the market for a child who cannot swallow tablets. Egypt OSPEN 1.0 MIU 12 F.C.TABS. SANDOZ 24.00 EGP (2.00/unit) OSPEN 1.5 MIU 12 F.C.TABS. SANDOZ 41.00 EGP (3.42/unit) ANTIBIOTIC - ALTERNATIVE 5. ERYTHROMYCIN [2nd line] Adult 500 mg four times daily x 14 days Peds Specialist paediatric infectious-disease dosing. Source Diphtheria - disease-level clinical article (diphtheria-clinical.txt) Why The article's other antibiotic of choice. Carried for completeness; see the caution on availability in Egypt. Caution Every oral erythromycin product in the Egyptian list carries the (N/A) suffix, meaning withdrawn - tablets, capsules and all six suspensions. Only topical acne preparations remain. The article names erythromycin first, but in Egypt penicillin G is the obtainable choice. Egypt ERYTHROMYCIN STEARATE 250MG 10 F.C. TABS. HI-PHARM 6.50 EGP (0.65/unit) -> discontinued ERYTHROCIN 500 MG 12 TABS. KAHIRA > ABBO... 12.00 EGP (1.00/unit) -> discontinued ERYTHROMYCIN STEARATE 500 MG 8 F.C. TAB. HI-PHARM 8.40 EGP (1.05/unit) -> discontinued ERYTHROCIN 250 MG TAB. KAHIRA > ABBO... 3.75 EGP [discontinued] ERYTHROMYCIN 500 MG 12 ENTRIC C. TABS. AMRIYA 11.00 EGP -> discontinued 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)