Sore Throat Richard Usatine, MD

What are causes of sore throats? Infectious - viral, bacterial, mycoplasma, chlamydiae, candida Allergic - allergic rhinitis Acid Reflux - GERD Trauma – e.g., swallowing a chicken bone Chemical irritants or burns Epiglottitis Thyroiditis Retropharyngeal abscess

Infectious Causes of Pharyngitis Adults Viral (including mononucleosis) 30-60% Group A Streptococcus 5-9% Group C, G, or F Streptococcus 0-18% N. gonorrhoeae 0-25% Mycoplasma 10-13% Chlamydia 9-20% pooled data from 11 studies

Strep throat versus viral pharyngitis ask about: fever, pain on swallowing physical exam: throat - exudate, palatal petechiae, injection, swelling neck - tender anterior cervical adenopathy children - strawberry tongue, sand paper rash

Why do we want to diagnose and treat GABHS? to prevent rheumatic fever: less than 200 cases of acute rheumatic fever per year in the US to prevent suppurative complications (e.g., peritonsillar abscess) to speed up recovery and shorten duration: treatment with antibiotics (only if started early in the clinical course) speeds symptomatic recovery of patients with culture-proven GABHS by about a half day to reduce spread to others

Downside of using antibiotics Promotes antibiotic resistance Adverse reactions such as allergy and anaphylaxis Costly compared to health education Patients do not need antibiotics to feel satisfied with the doctor-patient encounter (Hamm)

Case 1 A 25 year old man comes to your office with the complaint of a bad sore throat for 2 days. He has felt chills and fever today but has not measured his temperature. He has some pain on swallowing. He has a slight runny nose and denies cough and other symptoms. He was previously healthy. T= 38.5 PE: ears - TM's normal nose – clear neck - no cervical adenopathy lungs – clear

Case 1 Another strep throat

What is the differential diagnosis in order of likelihood? Strep Viral

Sensitivity and Specificity Strep throat+ sensitivity A/(A+C) Strep throat ‑ specificity D/(D+B) test + (Hx, PE or lab) A true positive B false positive test ‑ C false negative D true negative

Positive Predictive Value (PPV) Changes based on the prevalence in the population True positives/all positives Higher prevalence increases the PPV

How well does PE predict strep throat? Sensitivity Specificity Positive Predictive Value Anterior Cervical adenopathy .80 .55 .27 Tonsillar Exudate .65 .69 .31 Tonsillar Swelling .87 .39 .23 Injected Pharynx .97 .18 .20

How well does history predict strep throat? Sensitivity Specificity PPV enlarged cervical nodes .94 .27 .19 strep exposure .25 .88 absence of cough .83 .48 .22 absence of rhinorrhea .73 .20 fever > 38.3C .17 .33

History and Physical No individual item has sufficient predictive value on its own Need to combine items to get greater predictive value Purpose of a clinical decision rule

Clinical Prediction Rule for Strep Throat Fever over 38 C Absence of cough Tender ant. cervical adenopathy Tonsillar swelling or exudate Age< 15 y Age> 45 McIsaac modification of the Centor Criteria (added age) 1 -1

Probability of Strep throat based on points (pretest probability) -1 to 0 1 2 3 4 or 5 1% 10% 17% 35% 51%

How many points does our patient have? Fever over 38 C Absence of cough Tender ant. cervical adenopathy Tonsillar swelling or exudate Age< 15 y Age> 45 Total = 3 Pretest probability= 35% 1

What are the tests? Rapid strep test Throat culture Done in minutes in the office Throat culture Gold standard – how can you get false negatives or positives? ASO titer – not useful for practicing medicine

How to swab for rapid strep test or culture.

3 categories low probability of GABHS - no test, no treat intermediate probability - test high probability - treat, no test

Rapid Strep Test Done Result for patient in case one: positive

Antibiotic treatment PenVK 500 mg tid x 10 #30 Studies indicate increased failure rates of preventing acute rheumatic fever of 2 times with treatment of 7 days and 3 times with treatment of 5 days. Erythromycin or Azithromycin for patients allergic to penicillin

What symptomatic treatment could you offer the patient? Acetaminophen gargling with warm salt water throat lozenges fluids, warm or cold, can be soothing

Case 2 A 30 year old man comes to your office with a scratchy throat and a headache for one day. His nose is slightly stuffy and he has a non-productive cough. He denies allergies and fever. He smokes 1 ppd. VS : T= 37.1 PE: ears - TM's normal nose – clear mucus and boggy mucosa face - no sinus tenderness neck - tender adenopathy

Case 2 mild erythema with cobblestone appearance of posterior pharynx, left tonsillar exudate present Case 2

How many points does our patient have? Fever over 38 C Absence of cough Tender ant. cervical adenopathy Tonsillar swelling or exudate Age< 15 y Age> 45 Total = 2 Pretest probability= 17% 1

Rapid Strep Test Done Result is negative Symptomatic treatment

Case 3 A 6 year old girl is brought to your office with low grade fever, sore throat, and poor appetite for 3 days. Father states that she does not have cough or runny nose. No vomiting or diarrhea. She is allergic to Penicillin. PE : T = 38.2 P 110 ears - TM's normal nose - clear throat - tonsils - beefy red and almost touching in midline. Uvula in midline, no exudate, no petechiae neck - enlarged tender anterior cervical nodes lungs – clear skin - sandpaper rash prominent around axilla

Case 3 Case 3

Scarlet fever How do we treat this? What does this have to do with rabbits?

Case 4 A 19 year old woman comes to your office with 2 days of sore throat, cough, and runny nose. Patient feels feverish but has not taken her temperature. She has no other symptoms and no history of other medical problems. The patient very much wants penicillin. T = 37.4 P 80 ears - TM's normal nose - boggy red mucosa with clear mucus neck - shotty nodes lungs - clear

Case 4 Viral 19yo with rhinitis and cough too.

How many points does our patient have? Fever over 38 C Absence of cough Tender ant. cervical adenopathy Tonsillar swelling or exudate Age< 15 y Age> 45 Total = 0 Pretest probability= 1%

What do you do? No test No treat – no antibiotics Treat symptoms

Case 5 A 25 year old woman comes to your office with a severe sore throat for 4 days and has difficulty swallowing. She now feels very hot and has been off work for 2 days. Her neck also hurts. She denies cough and rhinitis. No known allergies. Patient appears to be in moderate distress but she is able to breath comfortably. T = 39.5 ears - normal nose - clear throat - it is difficult for the patient to open her mouth because of pain neck - bilateral anterior cervical adenopathy with right worse than left

Case 5 Case 5

Peritonsillar Abscess

Peritonsillar Abscess Another peritonsillar abscess, not a case

Case 6 A 16 year old girl is brought to your office by her mom for a fever and sore throat. She complains that it hurts to swallow and she has swollen glands. A friend was diagnosed with "mono" 3 weeks ago. Patient has no known history of mono. Patient denies cough and runny nose. Her temperature last night was 103 degrees F (oral). T = 39 100/65 P 100 neck - bilateral enlarged tender anterior cervical nodes and smaller posterior cervical adenopathy lymph nodes – axillary adenopathy lungs - clear abd - no splenomegaly

Case 6

Differential Diagnosis Mononucleosis Strep Throat Viral Consider a CBC and a monospot. EBV VCA-IgM is more sensitive but more expensive.

Case 7 A 41 year old man comes to your office with a painful throat and a headache for one day. No cough. T = 38.1 BP 150/90 P 70 ears - TM's normal nose - clear neck - right anterior cervical node is tender and enlarged lungs - clear

Case 7 deep erythema, palatal petechiae and no exudate, tonsillar swelling present

How many points does our patient have? Fever over 38 C Absence of cough Tender ant. cervical adenopathy Tonsillar swelling or exudate Age< 15 y Age> 45 Total = 4 Pretest probability= 51% 1

www.med.sc.edu:85/ fox/strep-thr.jpg

Case 1

Strep Throat Strep throat

Candida in a man with AIDS Candida pharyngitis in a man with AIDS

Viral Another viral pharyngitis – girl age 14

Herpangina Herpangina, little ulcers on the soft palate

Coxsackie A16 Virus www.netwave.or.jp/~jibika/ herpangina.jpg

Summary Use of clinical prediction rule to diagnose sore throat (useful in other diseases) Clinical prediction rule helps to establish pretest probability and put patient in one of three categories No test, no treat Test and treat based on result No test, just treat Use antibiotics for sore throat when probability of strep throat is above your treatment threshold

Photographs by: Richard Usatine, MD for slides 4, 12 and 14 Hospital Practice Web sites icarus.med.utoronto.ca/carr/manual/pta.html Atlas of Infectious Diseases

Useful web sites: MedRules has the pharyngitis prediction rule: http://www.palmgear.com/index.cfm?fuseaction=software.showsoftware&prodid=10959 Or get it at Ectopic Brain, a great site for other PDA software: http://pbrain.hypermart.net/