New GP Infectious Disease Flashcards

Question

A 23-year-old woman presents to her GP with a lesion on her lip. On examination, she has evidence of a vesicle that has burst and is healing over. Possible diagnosis?

Answer 1

Herpes simplex virus (HSV)

Answer 2

HSV-1 + HSV-2 **Oral herpes simplex** (AKA herpes simplex labialis) * Infection of mouth area + lips → often presenting as cold sores * HSV-1 (= most causes, 90%) **Genital herpes simplex** * = STI → resulting in genital ulcers * Can be either HSV-1 or HSV-2

Answer 3

HSV-1: detailed pathophysiology * HSV-1 infection is typically spread via saliva or other infected bodily secretions * Once caught, HSV-1 replicates at the site of infection and travels down nerves to the dorsal root ganglion where it can remain dormant * As such, HSV-1 can be reactivated, with recurrences reported typically 2-3 times per year HSV-2: detailed pathophysiology * HSV-2 is spread primarily via sexual contact * Similarly to HSV-1, HSV-2 lays dormant in the sheath of sensory nerves following initial infection, explaining why it can reactivate and symptoms can return later in life * Under the microscope, smear samples can show the 3Ms of HSV infection: M ultinucleation, M argination of the chromatin, and M olding of the nuclei

Answer 4

Signs: * Presence of **vesicles** on mucocutaneous surfaces which have ruptured which crust over and heal * **Submandibular lymphadenopathy** Symptoms: * **Lip ulceration: ‘cold sores’** * Malaise/fever * Sore throat * Paraesthesia/pain: these precede the lesion by 6-48 hours

Answer 5

Signs: * Presence of **multiple painful blisters** which burst and leave erosions/ulcers * Tender **inguinal lymphadenopathy** Symptoms: * Painful ulceration * Vaginal/urethra discharge * Malaise/fever * Groin pain * Neuropathic pain in the genital area

Answer 6

Signs: * **Cervical + submandibular lymphadenopathy** * Crops of **painful vesicles** on a red swollen base that often rupture and form **ulcers** on the pharyngeal and oral mucosa Symptoms: * Sore throat * Malaise/fever * Excessive salivation or drooling (especially in children) * Painful ulcers in the mouth

Answer 7

* Oral herpes → clinical diagnosis * Genital herpes → requires investigation * HSV **swabs** for **NAAT** (nucleic acid amplification tests) Consider STI screen

Answer 8

* **Simple analgesia**: paracetamol or ibuprofen * **Self-care advice**: avoid kissing and oral sex until lesions have fully healed and to avoid touching the lesions * **Do not prescribe** topical anaesthetic or analgesic preparations, mouthwash, or lip barrier preparations * **Antiviral treatment**: for patients who are **immunocompromised** or in individuals with a severe oral herpes simplex infection ## Footnote Topical preparations and mouthwash : can be considered as over the counter treatments but are not recommended as a prescribed medication

Answer 9

* Antiviral treatment: **Aciclovir** (within the first 5 days of he start of the genital HSV infection or while new lesions are forming; consider further antiviral treatment in recurrent infection) * **Self-care advice**: avoid sexual intercourse until lesions have cleared

Answer 10

**Caesarean section** (particularly those developing symptoms within 6 weeks of the expected delivery)

Answer 11

Suppressive therapy (e.g. daily suppressive **aciclovir 400 mg** TDS should be considered **from 36 weeks** of gestation)

Answer 12

RNA virus (Type A, B, C = affect humans) Type A + B = most common

Answer 13

* Type A has different H and N subtypes. Examples of A strains are: * **H1N1** (which caused the **Spanish flu pandemic of 1918** + **swine flu pandemic of 2009**) * **H5N1** (which causes **bird flu**). * Outbreaks of flu typically occur during the winter.

Answer 14

The flu vaccine is free on the NHS to people at higher risk of developing flu or flu-related complications: * Aged 65 and over * Young children * Pregnant women * Chronic health conditions, such as asthma, COPD, heart failure and diabetes * Healthcare workers and carers

Answer 15

The delay between exposure and symptoms is usually around 2 days. Typical presenting features include: * Fever * Lethargy and fatigue * Anorexia (loss of appetite) * Muscle and joint aches * Headache * Dry cough * Sore throat * Coryzal symptoms

Answer 16

Common cold vs influenza: * Influenza → **abrupt onset** * Common cold → gradual onset * Influenza → **fever** = typical * Common cold → fever = rare * Influenza → '**wiped out**' with **muscle aches + lethargy** * Common cold → continue many activities

Answer 17

* **Point-of-care tests** → detect viral antigens (give rapid result) → not sensitive as formal labs * **Viral nasal** or **throat swabs** → **polymerase chain reaction (PCR)**

Answer 18

Heathly patient → not risk of complications → supportive (fluid intake + rest) Patients at risk of complications: * Oral **oseltamivir** (twice daily for **5 days**) * Inhaled **zanamivir** (twice daily for **5 days**) Treatment needs to be started within 48 hours of the onset of symptoms to be effective. Post-exposure prophylaxis may be given where patients meet specific criteria: * It is started within 48 hours of close contact with influenza * Increased risk (e.g., chronic disease or immunosuppression) * Not protected by vaccination (e.g., it has been less than 14 days since they were vaccinated) Options for post-exposure prophylaxis are: * Oral **oseltamivir** 75mg once daily for **10 days** * Inhaled **zanamivir** 10mg once daily for **10 days**

Answer 19

* Otitis media, sinusitis and bronchitis * Viral pneumonia * Secondary bacteria pneumonia * Worsening chronic health conditions, such as COPD and heart failure * Febrile convulsions (young children) * Encephalitis