Is pain from shingles (herpes zoster) constant or intermittent?

Pain Characteristics in Shingles (Herpes Zoster)

Pain from shingles typically begins as a constant burning, tingling, or itching sensation during the prodromal phase (1-3 days before rash appears), then transitions to a mixed pattern of constant deep burning or aching pain with superimposed intermittent sharp, stabbing, or lancinating pain during the active phase and potential post-herpetic neuralgia. 1, 2

Typical Pain Progression in Shingles

• Prodromal Phase (Pre-rash): Pain typically precedes the appearance of the rash by 1-3 days, manifesting as constant burning, tingling, or itching sensations in the affected dermatome 1, 2
• Active Phase (With Rash): Once the characteristic unilateral vesicular rash develops, patients experience a combination of:
  • Constant deep, burning or aching pain in the affected area 1, 3
  • Intermittent sharp, stabbing, or lancinating pain that comes and goes 3, 4
• Resolution Phase: Pain typically decreases as lesions heal, with the entire course from prodromal symptoms to healing taking 2-4 weeks in immunocompetent hosts 2

Pain Characteristics in Post-Herpetic Neuralgia

• Post-herpetic neuralgia (PHN) occurs when pain persists for more than 3 months after the rash resolves 3
• PHN pain has multiple characteristics:
  • Constant deep, aching, or burning pain that is always present 3
  • Paroxysmal, lancinating (sharp, stabbing) pain that comes and goes 3, 4
  • Hyperalgesia (painful stimuli are more painful than expected) 3
  • Allodynia (pain from typically non-painful stimuli like light touch) 3, 5

Factors Affecting Pain Presentation

• Age: Older patients typically experience more severe and longer-lasting pain 1, 6
• Immune Status: Immunocompromised patients (HIV infection, chemotherapy, malignancies, chronic corticosteroid use) often have more severe and prolonged pain 1, 6
• Timing of Treatment: Early antiviral treatment (within 72 hours of rash onset) can reduce pain severity and duration 7, 6
• Location: Trigeminal or ophthalmic involvement often causes more severe pain 8, 6

Clinical Pearls and Pitfalls

• Key Pearl: The mixed nature of shingles pain (both constant and intermittent components) is an important diagnostic feature 1, 3
• Common Pitfall: Failing to recognize prodromal pain as potential shingles, especially in elderly patients where the rash may be subtle or delayed 1, 2
• Important Consideration: Even after the rash resolves, patients may continue to experience significant pain that requires ongoing management 7, 3
• Warning Sign: Persistent pain in a dermatomal distribution without rash (zoster sine herpete) can still represent shingles and should be treated accordingly 7

Treatment Implications

• The mixed nature of pain (constant and intermittent) often requires combination therapy targeting different pain mechanisms 3, 4
• For acute shingles pain:
  • Antiviral medications (acyclovir, valacyclovir, famciclovir) should be started within 72 hours of rash onset 7, 6
  • Pain management may include analgesics, anticonvulsants, and sometimes short-term corticosteroids 7, 6
• For post-herpetic neuralgia:
  • Multimodal approach with tricyclic antidepressants, anticonvulsants, topical agents (lidocaine, capsaicin), and sometimes opioids 3, 4

Understanding the complex and evolving nature of shingles pain helps guide appropriate treatment selection and timing to minimize suffering and prevent complications.