Can Herpes Labialis Develop on the Lips?
Yes, herpes labialis specifically develops on the lips and perioral skin—this is the defining characteristic of the condition. 1, 2, 3
Clinical Presentation and Location
Herpes labialis is characterized by recurrent vesicular eruptions that occur primarily on the lips and perioral (around the mouth) skin. 3 This is the classic and most common manifestation of HSV-1 infection affecting the orolabial region. 1, 2
Typical Lesion Evolution on the Lips
The disease follows a predictable pattern when it occurs on the lips:
- Prodromal phase: Patients experience itching, burning, or paresthesia at the site before visible lesions appear 2
- Active lesion phase: Classic grouped lesions evolve from papules → vesicles → ulcers → crusts on the lip surface 3
- Duration: The untreated course typically lasts 7-10 days 1
- Recurrence frequency: Lesions recur 1-12 times per year, triggered by sunlight, stress, or fever 1
Why This Matters Clinically
The lip location is what distinguishes herpes labialis from other HSV-1 manifestations. 1 While HSV-1 can cause infections elsewhere (such as genital herpes, herpetic whitlow, or HSV keratitis), the term "herpes labialis" specifically refers to the orolabial presentation on the lips. 1
Common Pitfall to Avoid
Do not confuse the presence of labial herpes (cold sores on the lips) with HSV encephalitis in adults—labial herpes in critically ill adults is merely a marker of critical illness and has no diagnostic specificity for encephalitis. 1 However, in children with primary HSV infection who develop encephalitis, active labial herpes may be noted as part of the clinical picture. 1
Diagnostic Approach
The diagnosis of herpes labialis is primarily clinical, based on the characteristic grouped vesicular lesions on the lips. 3 Laboratory confirmation with PCR or viral culture should be obtained when diagnostic certainty is required, but is not necessary for typical presentations. 2