Herpes simplex virus - Cellulitis DDx
See also in: Overview,AnogenitalAlerts and Notices
Important News & Links
Synopsis
Herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2) infections (cold sores, fever blisters, herpes gladiatorum, scrum pox, herpetic whitlow, herpes progenitalis) are common worldwide, usually affecting the orolabial and genital regions, although any skin area may be affected.
Infection is acquired through contact with contaminated saliva or other body fluids during periods of viral shedding. Primary infection denotes the initial inoculation episode, which may be subclinical or cause significant disease, usually in children. The virus establishes lifelong latency in the dorsal root ganglia. Clinical disease occurs with reactivation (spontaneously or with trauma, ultraviolet [UV] exposure, fever, or immunosuppression) of the latent virus, which travels from the nerve root to innervated skin regions. This occurs in 30%-50% of oral HSV infections and 95% of genital HSV infections. An individual may be coinfected with more than one type of HSV and in more than one location. HSV acquisition at a new site in a previously infected person is designated a nonprimary, first episode infection.
Ninety percent of adults are antibody positive to HSV-1. HSV-2 prevalence is lower, affecting almost a quarter of the US population. Women have a higher seropositivity to HSV-2 than men. Americans of African descent have a higher seropositive rate than other US population groups. Risk factors for genital HSV infection include having multiple sexual partners, lower educational and socioeconomic levels, a man who has sex with men, or HIV infection.
Symptoms of primary disease are usually more severe than recurrent disease and depend upon the site of inoculation. Localized adenopathy is common with primary infection. Disease occurs 3-7 days after exposure; recovery from a primary episode usually occurs in 2-6 weeks. Disseminated infection and pneumonitis may occur in the immunocompromised. Other complications include bacterial superinfection, radiculoneuropathy, encephalitis, hepatitis, and eczema herpeticum in patients with atopy. Viral folliculitis secondary to HSV (usually inoculated secondary to shaving) has been described. Pregnant individuals with primary HSV infection are at increased risk for severe illness, ie, dissemination and hepatitis, particularly in the third trimester.
Recurrent disease usually lacks constitutional symptoms. Itching, burning, tingling, or pain often precede the skin lesions. Complications include bacterial superinfection, eczema herpeticum, erythema multiforme, Bell palsy, aseptic meningitis, and encephalitis.
HSV infection in HIV-infected patients and other immunodeficiency states with T-cell defects is common and often presents with more severe and chronic disease and may be hypertrophic. Chronic nonhealing, painful ulcers occur, particularly in the perianal location. Others at risk for this include marrow and solid organ transplant patients and patients with lymphoma and leukemia.
Grouped, umbilicated vesicles and a history of recurrent "flares" should alert one to the possibility of this diagnosis over cellulitis.
Infection is acquired through contact with contaminated saliva or other body fluids during periods of viral shedding. Primary infection denotes the initial inoculation episode, which may be subclinical or cause significant disease, usually in children. The virus establishes lifelong latency in the dorsal root ganglia. Clinical disease occurs with reactivation (spontaneously or with trauma, ultraviolet [UV] exposure, fever, or immunosuppression) of the latent virus, which travels from the nerve root to innervated skin regions. This occurs in 30%-50% of oral HSV infections and 95% of genital HSV infections. An individual may be coinfected with more than one type of HSV and in more than one location. HSV acquisition at a new site in a previously infected person is designated a nonprimary, first episode infection.
Ninety percent of adults are antibody positive to HSV-1. HSV-2 prevalence is lower, affecting almost a quarter of the US population. Women have a higher seropositivity to HSV-2 than men. Americans of African descent have a higher seropositive rate than other US population groups. Risk factors for genital HSV infection include having multiple sexual partners, lower educational and socioeconomic levels, a man who has sex with men, or HIV infection.
Symptoms of primary disease are usually more severe than recurrent disease and depend upon the site of inoculation. Localized adenopathy is common with primary infection. Disease occurs 3-7 days after exposure; recovery from a primary episode usually occurs in 2-6 weeks. Disseminated infection and pneumonitis may occur in the immunocompromised. Other complications include bacterial superinfection, radiculoneuropathy, encephalitis, hepatitis, and eczema herpeticum in patients with atopy. Viral folliculitis secondary to HSV (usually inoculated secondary to shaving) has been described. Pregnant individuals with primary HSV infection are at increased risk for severe illness, ie, dissemination and hepatitis, particularly in the third trimester.
Recurrent disease usually lacks constitutional symptoms. Itching, burning, tingling, or pain often precede the skin lesions. Complications include bacterial superinfection, eczema herpeticum, erythema multiforme, Bell palsy, aseptic meningitis, and encephalitis.
HSV infection in HIV-infected patients and other immunodeficiency states with T-cell defects is common and often presents with more severe and chronic disease and may be hypertrophic. Chronic nonhealing, painful ulcers occur, particularly in the perianal location. Others at risk for this include marrow and solid organ transplant patients and patients with lymphoma and leukemia.
Grouped, umbilicated vesicles and a history of recurrent "flares" should alert one to the possibility of this diagnosis over cellulitis.
Codes
ICD10CM:
B00.1 – Herpesviral vesicular dermatitis
SNOMEDCT:
88594005 – Herpes simplex
B00.1 – Herpesviral vesicular dermatitis
SNOMEDCT:
88594005 – Herpes simplex
Look For
Subscription Required
Diagnostic Pearls
Subscription Required
Differential Diagnosis & Pitfalls
To perform a comparison, select diagnoses from the classic differential
Subscription Required
Best Tests
Subscription Required
Management Pearls
Subscription Required
Therapy
Subscription Required
References
Subscription Required
Last Updated:07/11/2023
Patient Information for Herpes simplex virus - Cellulitis DDx
Premium Feature
VisualDx Patient Handouts
Available in the Elite package
- Improve treatment compliance
- Reduce after-hours questions
- Increase patient engagement and satisfaction
- Written in clear, easy-to-understand language. No confusing jargon.
- Available in English and Spanish
- Print out or email directly to your patient
Upgrade Today
Herpes simplex virus - Cellulitis DDx
See also in: Overview,Anogenital