Herpes Simplex: Symptoms, Types, Causes and Treatment

Herpes simplex is a common viral infection that affects millions of people worldwide. Despite its prevalence, there remains significant confusion and stigma around the disease. Understanding herpes simplex—how it presents, its two main types, what causes it, and how it can be treated—is essential for both those affected and the general public. This article provides an in-depth, evidence-based exploration of herpes simplex, synthesizing the latest clinical and epidemiological research.

Symptoms of Herpes Simplex

Herpes simplex virus (HSV) infections can present with a range of symptoms, from barely noticeable issues to severe and distressing illness. The majority of infections are asymptomatic, but when symptoms do occur, they are often localized, recurring, and can greatly affect quality of life.

Symptom	Area Affected	Frequency/Severity	Source(s)
Blisters	Mouth, genitals, eyes	Common in symptomatic cases	1 2 3 5 7
Pain/Itching	Lesion site	Very common, especially in initial episode	1 2 3
Ulcers	Genitals, mouth, eyes	Common, can be extensive	1 2 3 5
Systemic symptoms	Whole body	Fever, malaise in primary infection	1 2 3 5
Lymphadenopathy	Groin, neck	Common in primary episodes	1 3 5
Dysuria	Genitals/urinary tract	Noted in genital herpes	1 3 5
Eye symptoms	Eyes	Redness, photophobia, watering	2 3 14
Recurrences	Mouth, genitals	Frequent, often milder or asymptomatic	1 3 5 7
Complications	CNS, eyes, neonates	Meningitis, encephalitis, keratitis	1 2 3 5 9 12

Table 1: Key Symptoms

Symptom Presentation and Course

Herpes simplex often starts with a burning or tingling sensation at the site of infection, followed by the appearance of small, painful blisters. These blisters can burst, leaving shallow ulcers that eventually crust over and heal. The mouth (herpes labialis, “cold sores”) and genitals are the most common areas affected, but HSV can also cause eye infections (herpes keratitis), herpetic whitlow (fingers), and in severe cases, infections of the nervous system or newborns 1 2 3 5 9 14.

Systemic and Local Symptoms

• Primary infection often causes more severe symptoms, including fever, malaise, and tender lymph nodes, especially in genital herpes. Women tend to experience more severe symptoms than men 1 3 5.
• Oral herpes frequently presents as painful vesicles and ulcers around the lips and inside the mouth, sometimes with fever and swollen neck glands 3 5.
• Genital herpes causes blisters and ulcers on the genitals, anus, or surrounding areas, often accompanied by pain, itching, dysuria, and inguinal lymphadenopathy 1 3 5.
• Eye involvement leads to redness, watering, irritation, and sometimes blurred vision or photophobia. Eyelid vesicles and ulcers may occur. Severe cases can cause keratitis, potentially threatening vision 2 3 14.

Recurrences and Complications

After the initial episode, HSV remains latent in sensory nerve ganglia and can reactivate periodically, causing recurrent lesions—typically milder and shorter in duration. Many recurrences are asymptomatic, especially in genital herpes 1 3 5 7. Complications can include aseptic meningitis, herpetic encephalitis, and, in neonates, severe systemic disease 1 5 9 12.

Types of Herpes Simplex

Herpes simplex virus exists in two major forms, each with its characteristic patterns of infection, yet with considerable overlap due to changing epidemiology and behaviors.

Type	Primary Infection Site	Typical Manifestations	Source(s)
HSV-1	Mouth, lips, face	Cold sores, gingivostomatitis, ocular herpes	3 4 5 6 7 8 9 10 11 13 14
HSV-2	Genitals, perianal area	Genital herpes, neonatal herpes	3 4 5 6 7 8 9 10 11 13 14
Both	CNS, eyes, neonates	Encephalitis, keratitis, systemic	3 5 9 10 12 14
Recurrent	Site of primary infection	Localized lesions, often milder	1 3 5 7 13

Table 2: Types of Herpes Simplex

HSV-1: More Than Just “Cold Sores”

HSV-1 has traditionally been associated with oral infections—cold sores or fever blisters around the mouth and face. It is often acquired in childhood through nonsexual contact. However, HSV-1 can also cause genital herpes, especially in young adults, due to changes in sexual practices 3 4 5 6 7 8 9 10 11 13 14.

• Orofacial herpes (HSV-1): The classic presentation, with painful blisters and ulcers on the lips and inside the mouth (herpetic gingivostomatitis) 3 5.
• Ocular herpes (HSV-1): The leading cause of infectious blindness in developed countries, presenting as keratitis or conjunctivitis 2 3 14.
• Genital herpes (HSV-1): Increasingly recognized, especially in developed countries among young women 6 7 8.

HSV-2: The Traditional Genital Herpes Virus

HSV-2 is mainly associated with genital infections, typically acquired through sexual contact. It is the most common cause of recurrent genital herpes 3 4 5 6 7 8 9 10 11 13 14.

• Genital herpes (HSV-2): Characterized by painful, grouped vesicles and ulcers in the genital and perianal areas, often with pronounced first-episode symptoms 1 3 5.
• Neonatal herpes (HSV-2): Can cause severe infections in newborns if transmitted during childbirth 5 9 14.

Overlapping Manifestations and Unusual Presentations

Both HSV-1 and HSV-2 can cause severe complications, including encephalitis, meningitis, and disseminated disease in immunocompromised individuals 3 5 9 10 12 14. Recurrent disease tends to occur at the site of the initial infection and is typically less severe, but can still be a significant burden 1 3 5 7 13.

Changing Epidemiology

Recent studies show HSV-1 is now a leading cause of genital herpes in young women in industrialized countries, reflecting shifting patterns of transmission 6 7 8.

Causes of Herpes Simplex

Herpes simplex is caused by two closely related viruses, HSV-1 and HSV-2. Understanding how the virus spreads and why some people have repeated outbreaks is important for prevention and management.

Cause/Transmission	Description	At-Risk Populations	Source(s)
HSV-1/HSV-2 Virus	Double-stranded DNA viruses, alphaherpesvirus family	All ages, sexually active adults	3 4 5 10 12 14
Direct contact	With infected lesions, saliva, genital or oral secretions	Children, sexually active adults	3 5 6 8 9 14
Asymptomatic shedding	Virus present and transmissible without symptoms	All, especially partners of infected	5 7 8 18
Latency/Recurrence	Virus remains dormant in sensory ganglia, reactivates	Those with prior infection	3 4 10 12 13 14

Table 3: Causes and Transmission

The Viruses: HSV-1 and HSV-2

HSV-1 and HSV-2 are large, double-stranded DNA viruses belonging to the alphaherpesvirus subfamily. They are morphologically similar but differ in their usual site of infection and epidemiology 3 4 10 12 14.

• HSV-1 infects mainly the oral and facial region, but increasingly the genitals.
• HSV-2 predominantly infects the genital and perianal area.

Modes of Transmission

The primary mode of transmission is direct contact with an infected person’s lesion, mucosal surface, or their oral/genital secretions 3 5 6 8 9 14. This can occur through:

• Kissing (oral-oral transmission)
• Sexual contact (oral, vaginal, or anal sex)
• Mother to infant (during childbirth)
• Autoinoculation (spreading from one site to another, e.g., from mouth to eye)

Asymptomatic Shedding

A significant challenge in controlling herpes simplex is that individuals can shed and transmit the virus even when they have no visible symptoms—known as asymptomatic shedding. Estimates suggest HSV-2 can be shed asymptomatically on 3–5% of days, and even more frequently when detected with sensitive PCR methods 5 7 8 18.

Latency and Recurrence

After initial infection, HSV enters nearby sensory nerves and travels to the nerve ganglia, where it becomes dormant (latent). The virus can reactivate—often triggered by stress, illness, sunlight, or hormonal changes—resulting in recurrent outbreaks, usually at the original site 3 4 10 12 13 14.

• Genetic factors may influence susceptibility and recurrence rates 4 12.
• Immunosuppression (e.g., HIV, chemotherapy) increases the risk of severe or recurrent disease 9 12.

Treatment of Herpes Simplex

While there is no cure for herpes simplex, effective treatments are available to reduce symptom severity, shorten outbreak duration, and decrease the risk of transmission. Ongoing research is targeting even better therapies and possible cures.

Treatment Approach	Example/Details	Effectiveness/Considerations	Source(s)
Antiviral drugs	Acyclovir, valacyclovir, famciclovir	Reduce symptoms, shorten duration, suppress recurrences	4 5 9 15 16 17 18 19
Topical treatments	Local anesthetics, antiviral creams	Symptom relief, limited effect on viral replication	4 15
Suppressive therapy	Daily antivirals	Reduces recurrences by up to 80%, decreases viral shedding	4 5 9 15 16 18 19
Prevention	Safe sex, condoms, antiviral prophylaxis in pregnancy	Reduces transmission risk, especially to neonates	4 5 9 18 19
Emerging therapies	Vaccines, gene editing, new antivirals	Under development, not yet standard of care	18 19

Table 4: Treatment Approaches

Antiviral Medications

The mainstay of herpes simplex treatment is antiviral therapy. The three most commonly used oral agents are acyclovir, valacyclovir, and famciclovir. These drugs:

• Inhibit viral replication, speeding healing and reducing the severity of outbreaks.
• Are effective in both primary and recurrent infections.
• Can be used episodically (during outbreaks) or as daily suppressive therapy to prevent recurrences and reduce transmission risk 4 5 9 15 16 17 18 19.

Suppressive Therapy

For individuals with frequent recurrences, daily antiviral therapy can reduce outbreaks by up to 80% and completely suppress them in about 25–30% of patients. Suppressive therapy also reduces, but does not eliminate, asymptomatic viral shedding 4 5 9 15 16 18 19.

Special Considerations

• Pregnancy: Antiviral suppression in late pregnancy is recommended for women with genital herpes to prevent neonatal transmission 4 5 9.
• Immunocompromised patients: May require higher doses or intravenous therapy. Resistance to acyclovir can occur, especially in this group 5 9 18.

Symptom Relief and Supportive Care

Topical anesthetics and antiviral creams can provide local relief but are less effective than systemic therapy for severe or genital disease 4 15.

Prevention and Reducing Transmission

• Condom use and limiting sexual contact during outbreaks are important for reducing transmission.
• Antiviral prophylaxis can be considered for partners of infected individuals and in pregnancy 4 5 9 18 19.
• Education on recognizing prodromal symptoms and avoiding triggers.

Future Directions

Research efforts are ongoing to develop vaccines, microbicides, and potentially even gene-editing therapies (such as CRISPR/Cas9) aimed at eradicating latent infection. While these are promising, they are not yet available for routine clinical use 18 19.

Conclusion

Herpes simplex is a common and often misunderstood infection. Understanding its symptoms, types, causes, and available treatments can empower individuals to better manage the disease and reduce its impact.

Key Takeaways:

• Herpes simplex causes a spectrum of symptoms, from mild or unnoticed to severe and life-altering 1 2 3 5 9 14.
• There are two main types: HSV-1 (traditionally oral, now increasingly genital) and HSV-2 (traditionally genital) 3 4 5 6 7 8 9 10 11 13 14.
• The viruses are transmitted through close contact, often during asymptomatic shedding, and establish lifelong latency with potential for recurrences 3 4 5 6 7 8 9 10 12 13 14 18.
• Effective antiviral treatments exist—both episodic and suppressive—helping to control symptoms and limit transmission 4 5 9 15 16 17 18 19.
• Prevention includes safe sex practices, education, and targeted antiviral use in certain populations. Promising new therapies are under development 4 5 9 18 19.

With greater awareness and continued research, the burden of herpes simplex can be further reduced and the quality of life for those affected significantly improved.