Can herpes and small ulcers occur on one leg?

Herpes and Small Ulcers Can Occur on One Leg

Yes, herpes virus infections, particularly herpes zoster (shingles), can manifest as small ulcers on one leg following a dermatomal distribution pattern. 1

Clinical Presentation of Herpes on the Leg

• Herpes zoster (shingles) is characterized by a unilateral, vesicular eruption with dermatomal pain that often precedes the skin findings by 24-72 hours 2, 1
• The rash follows a specific nerve pathway (dermatome) and does not cross the midline of the body
• Lesion progression follows a predictable pattern:
  • Early lesions begin as erythematous macules
  • Rapidly evolve to papules and then vesicles
  • Progress to thin-walled vesicles and pustules
  • Finally become small ulcers 2

Distinguishing Features

• Dermatomal distribution: Herpes zoster typically affects a single dermatome on one side of the body 2, 1
• Prodromal symptoms: Pain, burning, or tingling in the affected area often precedes visible lesions by several days 1
• Lesion characteristics: Grouped vesicles on an erythematous base that may coalesce and ulcerate 2
• Self-limiting course: New vesicle formation typically occurs for 3-5 days, followed by pustulation and crusting 1

Differential Diagnosis for Leg Ulcers

When evaluating small ulcers on one leg, consider these alternatives:

1. Vascular causes (most common - 80% of leg ulcers) 3, 4:

   • Venous insufficiency (typically medial ankle)
   • Arterial occlusive disease (typically distal foot/toes)
   • Mixed arterial-venous ulcers

2. Infectious causes:

   • Herpes zoster/simplex
   • Ecthyma (bacterial infection) 3

3. Inflammatory conditions:

   • Pyoderma gangrenosum (deep excavating ulcerations) 2
   • Vasculitis 3, 5
   • Necrobiosis lipoidica 3

4. Malignancy:

   • Squamous cell carcinoma 3

Diagnostic Approach

For suspected herpes infection on the leg:

• Clinical examination: Look for characteristic grouped vesicles/ulcers in a dermatomal pattern 1
• Laboratory confirmation (if diagnosis is uncertain):
  • Viral culture
  • PCR for HSV/VZV DNA
  • Direct immunofluorescence 1
  • Tzanck preparation (shows multinucleated giant cells but doesn't differentiate virus types) 1
• Biopsy may be needed for atypical presentations or non-healing lesions 5

Treatment of Herpes Zoster on the Leg

• Antiviral therapy: High-dose intravenous acyclovir is the treatment of choice for immunocompromised patients 2
• For immunocompetent patients with mild disease:
  • Oral acyclovir, famciclovir, or valacyclovir 2
  • Treatment should be started within 72 hours of rash onset for maximum efficacy 1
• Pain management: Critical component of treatment as herpes zoster can cause significant pain 1

Important Considerations

• Immunocompromised patients are at higher risk for more severe, disseminated disease 1
• Post-herpetic neuralgia (persistent pain after rash healing) is a common complication, especially in older adults 1
• Recurrent lesions in the same location should raise suspicion for herpes simplex rather than zoster 2
• Atypical presentations may require biopsy for definitive diagnosis 6

Prevention

• Zoster vaccine is recommended for prevention in eligible individuals 1
• For recurrent herpes simplex, suppressive antiviral therapy may be indicated if episodes occur frequently (≥6 per year) 1

Remember that while herpes can present as ulcers on one leg, other conditions can have similar appearances. Proper diagnosis is essential for appropriate management.