Source / episode info
- **Episode:**626
- **Title:**DIP Ep 626: The Clutch Herpes Podcast (Step 1-3), Part A
- **Published:**2025-11-24
- Source:Episode page
One-liner
This episode provides an integrated review of HSV infections, emphasizing the association between HSV-1 and oral/respiratory sources, its tendency to cause temporal lobe encephalitis via trigeminal ganglion latency, and high-yield differential diagnoses for skin rashes (EM vs SJS/TEN) and facial pain syndromes (Trigeminal Neuralgia vs Cluster Headache).
High-yield summary
- HSV-1 Association: HSV-1 is most commonly acquired from saliva/respiratory secretions, making dental professionals (dentists, hygienists) a classic source of infection.
- CNS Manifestations: HSV encephalitis typically involves the temporal lobes and is strongly associated with seizures and hemorrhagic findings in the CSF.
- Vagus Nerve Latency: Herpes Zoster Ophthalmicus (HZO) specifically results from reactivation due to latency in the first branch of the trigeminal nerve, the ophthalmic nerve ({CN V}_1).
- Antiviral Resistance: If HSV is resistant to acyclovir (due to thymidine kinase mutation), treatment must be switched to foscarnet, a pyrophosphate analog that bypasses the need for thymidine kinase activation.
- EM vs SJS/TEN: Erythema Multiforme (EM) is typically Nikolsky-negative, whereas Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are Nikolsky-positive.
- Trigeminal Pain Syndromes: Cluster headaches are classified as Trigeminal Autonomic Cephalalgia; they present with unilateral headache accompanied by ipsilateral autonomic symptoms (e.g., tearing, redness).
Learning objectives
- Differentiate the clinical presentations and sources of HSV-1 versus HSV-2 infections.
- Identify the specific branch of the trigeminal nerve responsible for Herpes Zoster Ophthalmicus (\text{CN V}_1).
- Recognize the key features, pathophysiology, and differential diagnoses (SJS/TEN vs EM) of acute cutaneous eruptions.
- Differentiate between Trigeminal Neuralgia and Cluster Headache, including their management protocols.
- Select the appropriate antiviral agent for HSV encephalitis, especially in cases of thymidine kinase resistance.