Background. Herpesviruses are among the most common human pathogens that cause a variety of diseases, including herpetic stomatitis, ophthalmic herpes, genital herpes, chickenpox, and shingles. Despite the availability of several effective medicines, such as acyclovir and valacyclovir, there is a need for the development of new medications with increased efficacy, reduced toxicity, and the ability to overcome viral resistance. The aim of the study was to identify and evaluate the antiviral activity of naturally occurring compounds against the herpes simplex virus in vitro. Results. Echinacea and hawkweed extracts demonstrated the most pronounced antiviral protection against the herpes simplex virus. Among pure chemical compounds, caffeic acid was found to be the most active against herpes simplex virus type 2. Conclusion. The obtained data demonstrate the potential of plant compounds for the development of new treatments for herpes infections. Among the compounds studied, echinacea and hawkweed extracts are the most promising and can be considered as candidates for the development of natural antiherpetic medications.

Effect of neonatal BCG vaccination on oral herpes in early childhood: A nested study within a randomised controlled trial.

Varicella-zoster virus (VZV) is the etiological agent of chickenpox and herpes zoster, while herpes simplex virus 1 (HSV-1) causes oral and genital herpes. Both infections manifest with skin blisters from which the viruses are transmitted to new hosts either via aerosol (VZV) or skin microabrasions (HSV-1). VZV reaches the skin through the blood route, and in the skin epidermis it first infects undifferentiated keratinocytes of the basal layer. Conflicting evidence exists for HSV-1, making it unclear whether HSV-1 infects undifferentiated or differentiated keratinocytes. Here, we developed in vitro models of primary human epidermal keratinocytes' differentiation to recapitulate infection of distinct layers of the epidermis by VZV and HSV-1. Our data show that replication of both viruses is restricted, VZV more than HSV-1, if initial infection occurs in differentiated keratinocytes, but not if initial infection occurs in basal undifferentiated keratinocytes. Like VZV, HSV-1 downregulates expression of proteins associated with keratinocyte differentiation, such as the suprabasal keratin K10. However, whereas downregulation of K10 occurs soon after VZV infection and before the virus has replicated, HSV-1-mediated K10 downregulation appears to require full viral replication. These observations provide insights into the potential for VZV and HSV-1 interactions with epidermal differentiation to yield strategies for developing host and pathogen-directed antiviral agents.

IL-17 inhibitors are increasingly used in dermatologic and autoimmune diseases, yet the risks of associated oral complications remain unclear. PubMed, Embase, Web of Science, and ClinicalTrials.gov were comprehensively searched. The primary outcome was the incidence of oral complications following IL-17 inhibitors therapy. A meta-analysis was conducted using random-effects models. A total of 106 clinical trials involving 57,017 participants were included. Oral mucosal infections were the most frequently observed complications. Meta-analysis was performed to evaluate the incidence of oral candidiasis and oral herpes, showing the pooled incidence of 4.73% (95% CI: 3.42-6.22) and 2.94% (95% CI: 2.50-3.42), respectively. Subgroup analysis indicated a higher risk of oral candidiasis with bimekizumab compared to secukinumab. Notably, the meta-analysis for oral candidiasis demonstrated high heterogeneity (I2 = 93.8%). Besides, bacterial odontogenic diseases (dental caries, pulpitis, abscesses, gingivitis, and periodontitis) and neuropathic disorders (trigeminal neuralgia and facial paralysis), neoplasm (lip neoplasms and tongue squamous cell carcinoma), were reported more frequently in IL-17 inhibitors users. IL-17 inhibitor administration is associated with an elevated incidence of oral complications, particularly oral candidiasis and herpetic infections, highlighting the importance of clinician awareness and assessment of oral complications during IL-17 inhibitors therapy.

Human herpesvirus infections are among the most common viral diseases in the world and are character-ised by their ability to persist in the host's body for life, forming a latent state. According to the WHO, about 67% of the population under the age of 50 is infected with herpes simplex virus type 1, with clinically mani-fested forms observed only in some carriers, and only a small percentage of patients seek medical help. This leads to late diagnosis, fragmented therapy, and a lack of a personalized approach to preventing recurrence. In conditions of prolonged stress, in particular the COVID-19 pandemic and the military conflict in Ukraine, the problem of psycho-emotional exhaustion of the population is becoming increasingly relevant. It has been proven that chronic stress contributes to immunosuppression, disruption of neuroendocrine regula-tion, and reactivation of latent herpesviruses, which can clinically manifest as recurrent herpetic stomatitis. Psycho-emotional disorders are also associated with the development of vegetative-visceral dysfunctions, in particular cardiac, gastrointestinal and infectious-respiratory disorders, which emphasizes the systemic na-ture of the problem. This study aimed to investigate and analyze the relationship between chronic anxiety and the clinical manifestations of recurrent herpetic stomatitis in young adults. This study was designed as a cross-sectional questionnaire-based survey to evaluate the association between chronic psycho-emotional stress levels and the occurrence of clinically manifested recurrences of oral herpetic infection. The study pro-tocol adhered to established bioethical principles and was conducted with the voluntary informed consent of all participants. The study involved 178 respondents aged 21 years and older who permanently reside in Ukraine and have a medical background. Data collection was conducted remotely using the Google Forms platform at Poltava State Medical University. The relative homogeneity of the sample in terms of age and educational characteristics contributed to the reliability of the comparative analysis of psycho-emotional and clinical indicators. The results demonstrated that a moderate level of perceived chronic stress predominates within the study population, reflecting the substantial psycho-emotional burden associated with contemporary socio-professional conditions. Clinically manifest herpetic lesions of the oral mucosa and lips were identified in fewer than 25% of respondents, consistent with the predominance of latent or subclinical infection despite the high seroprevalence of herpes simplex virus. A tendency toward a higher frequency of recurrences was observed among individuals with elevated anxiety levels and chronic stress. The practical significance of the study lies in increasing awareness among healthcare professionals of the role of psycho-emotional fac-tors in the course of chronic recurrent herpetic stomatitis. The application of structured questionnaires to as-sess the psychological status of patients enables to develop a more personalized approach to therapeutic and preventive strategies, optimizes comprehensive treatment, and contributes to reducing recurrence rates. The findings may serve as a foundation for the development of individualized patient management protocols incorporating modern approaches, including photobiomodulation with a diode laser.

Introduction: Mycoplasma pneumoniae is a common cause of community-acquired pneumonia in children, with up to 30% developing extrapulmonary manifestations, including mucocutaneous disease. Mycoplasma-induced rash and mucositis (MIRM) is a distinct clinical entity characterized by prominent mucositis and limited skin involvement, typically affecting the oral, ocular, and urogenital mucosa. While most cases are self-limited, severe presentations requiring intensive care are rare. Description: An 8-year-old previously healthy male presented with fever, cough, and progressive dyspnea, admitted to the pediatric ward for presumed Mycoplasma pneumonia and primary HSV infection. Over the following 48 hours, the patient developed worsening symptoms including bilateral conjunctival injection with hemorrhage, extensive oral and genital ulceration, and a diffuse erythematous maculopapular rash with bullous lesions on extremities. Concern for SJS prompted transfer to the PICU for closer monitoring and management. In the PICU, the patient exhibited signs of respiratory distress requiring non-invasive mechanical ventilation (BiPAP). He required multimodal IV analgesia due to severe mucosal pain, and was started and had a prolong course of total parenteral nutrition given his inability to tolerate oral intake. Infectious and autoimmune workups were initiated. Dermatology consultation and a skin punch biopsy revealed superficial perivascular dermatitis with rare eosinophils, findings consistent with MIRM. The patient was treated with IVIG, in addition to supportive care. Over the next several days, he showed marked improvement in respiratory status and mucocutaneous lesions. He was weaned off respiratory and nutritional support. He was discharged home in stable condition with complete clinical resolution. Discussion: This case highlights a rare and severe presentation of MIRM with respiratory compromise, an occurrence seen in fewer than 5% of pediatric cases. Differentiating MIRM from SJS is essential, as management and prognosis differ. While supportive care remains the mainstay of treatment, immunomodulatory therapies such as IVIG may be beneficial in select cases. Increased recognition of MIRM’s clinical spectrum is critical to avoid misdiagnosis, guide appropriate management, and optimize outcomes.

Pharyngo-laryngeal herpes zoster (HZ) is a rare but clinically important manifestation of varicella-zoster virus (VZV) reactivation. Unlike the well-described Ramsay Hunt syndrome, its neurological spectrum and outcomes remain poorly characterized. This study aimed to clarify patterns of cranial nerve involvement, recovery outcomes, and diagnostic challenges in pharyngo-laryngeal HZ, representing the largest single-center series to date. We retrospectively reviewed 34 patients diagnosed with pharyngo-laryngeal HZ at a tertiary referral hospital in Japan between July 2007 and June 2025. VZV reactivation was confirmed serologically in all cases. Clinical features, affected cranial nerves, treatments, and recovery outcomes were analyzed. Neurological recovery was defined as complete resolution of paralysis, and swallowing recovery as tolerance of the pre-onset diet. The cohort comprised 24 men and 10 women (mean age, 61.7 years). Herpetic lesions were identified in 23 patients, while 11 (32 %) presented without rash and were diagnosed with zoster sine herpete, underscoring the diagnostic value of serology. The glossopharyngeal (IX) and vagus (X) nerves were most frequently affected (59 % each), followed by the facial nerve (24 %). Dysphagia occurred in 22 patients (65 %), with 5 requiring nutritional support and 2 developing aspiration pneumonia. Among 25 patients with cranial nerve paralysis, only 14 (56 %) achieved complete recovery. Laryngeal paralysis resulting from the X nerve impairment demonstrated the poorest prognosis, with a recovery rate of 50 %, although none required surgical intervention. In contrast, all cases of facial paralysis recovered fully, often after delayed onset following IX/X nerve symptoms. Incomplete recovery was more common in older patients and those who did not receive combined antiviral and corticosteroid therapy, though differences were not statistically significant. Overall, dysphagia resolved in 21 of 22 patients (95 %), but recovery was frequently prolonged, with most requiring >2 weeks of swallowing rehabilitation before resuming oral intake. Pharyngo-laryngeal HZ is a distinct clinical entity typically manifesting as cranial polyneuropathy. The IX and X nerves are most often involved, with laryngeal paralysis associated with poorer outcomes. A substantial proportion of patients experience severe or prolonged dysphagia, necessitating nutritional support and rehabilitation. The frequent occurrence of zoster sine herpete highlights the critical role of serological testing in diagnosis. These findings emphasize that pharyngo-laryngeal HZ can cause severe, lasting morbidity, warranting early recognition, aggressive treatment, and preventive strategies, including zoster vaccination.

The aim of the present study was to investigate the prevalence of oral manifestations among patients undergoing chemotherapy. A systematic review was conducted and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The review was registered in PROSPERO, under registration number CRD42024564007. Two independent reviewers conducted searches in the PubMed, Embase, and Scopus databases as well as Google Scholar for grey literature in July 2024. Inclusion criteria comprised cross-sectional studies that evaluated oral manifestations associated with chemotherapy. Risk of bias was assessed using JBI Critical Appraisal tool for cross-sectional studies. Synthesis of the results was performed using the MedCalc software program. Twenty-four cross-sectional studies were included. After the analysis of the results, the pooled prevalence was estimated for the following oral manifestations: oral mucositis (42.15%); xerostomia (39.92%); dysgeusia (49.62%); candidiasis (24.11%); oral herpes (7.98%); oral ulcer (31.40%); gingivitis (56.15%); dysphagia (28.28%); halitosis (19.55%); oral pain (22.78%). The evidence suggests that the prevalence oral manifestations is high in patients undergoing chemotherapy. However, the results should be interpreted with caution due to the considerable heterogeneity among the studies.

BackgroundThe early and accurate diagnosis and management of common orofacial conditions is essential for effective dental care. However, junior dentists often lack confidence and practical skills in this area. This study aimed to assess the impact of an educational lecture on dental interns’ competency in diagnosing and managing prevalent orofacial diseases.MethodsThis study was conducted among dental interns at King Abdulaziz University, Saudi Arabia. A total of 161 newly graduated interns were invited to participate. An evidence-based, one-hour interactive online lecture involving common orofacial conditions was delivered by a certified oral medicine consultant. Participants completed a validated 40-item questionnaire at three time points: before the lecture, immediately after the lecture, and two months after the lecture. The questionnaire was designed to assess diagnostic and management skills using 20 clinical scenarios. Diagnostic competency score was based on the percentage of correct responses to 20 diagnostic multiple-choice questions (MCQs), and a management competency score was based on the percentage of correct responses to 20 management MCQs. Descriptive statistics and weighted kappa analyses were conducted by employing SPSS®, with significance set at p < 0.05.ResultsAmong the 161 participants, 91 interns (56.5%) completed all the stages. Following the intervention, overall competency scores significantly increased (from 78% at baseline to 91% immediately after the lecture), with a relative improvement of approximately 13% being observed (p < 0.001); moreover, the scores remained 8.5% higher than those at baseline at the two-month evaluation. Diagnostic accuracy demonstrated a notable improvement of 12.5% (p < 0.001) following the intervention and remained higher than baseline at follow-up. The greatest improvement in the diagnosis was observed for herpes labialis (+ 53.1%), irritational fibroma (+ 32.1%), and leukoedema/morsicatio buccarum (+ 20%). Management competency improved by 13.5% (p < 0.001) immediately after the lecture, followed by a decrease of 6% at the two-month follow-up. The greatest improvement was observed in the management of recurrent aphthous stomatitis (+ 36.6%). No significant differences were observed in terms of sex or grade point average (GPA).ConclusionThe educational lecture significantly enhanced the ability of dental interns to diagnose and manage common orofacial conditions. Given the importance of timely diagnosis and appropriate management in reducing the severity of common oral lesions, the findings of this study provide valuable insights. The results suggest that such targeted educational interventions should be integrated into continuing dental education programs to enhance clinical competence among practitioners.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12903-026-07662-7.

Prevalence and risk of oral adverse outcomes in patients with COVID-19: a retrospective real-world cohort study.

Oral adverse events associated with anti-tumor necrosis factor-alpha therapies: using a large real-world dataset.

Herpes simplex virus type 1 (HSV‐1) is responsible for the majority of cold sores, herpetic keratitis‐induced blindness, profound skin lesions, and encephalitis that can be fatal. Currently, acyclovir and its derivatives are the first‐line therapy for the treatment of HSV‐1 infection. But there are drawbacks to these treatments: limited efficacy against drug‐resistant strains of the virus. Hence, it is of critical importance to explore and develop new antiviral drugs for HSV‐1. In the present study, we explored whether tungsten oxide nanoparticles (WO3NPs) were potent inhibitors of HSV‐1 infection as a new class of agent. WO3NPs were characterized by X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FE‐SEM), Fourier transform infrared (FTIR) spectroscopy, and zeta potential analysis. Cytotoxicity of Vero cells caused by WO3NPs was determined by methyl thiazolyl tetrazolium (MTT) assay. The quantitative real‐time polymerase chain reaction (qRT‐PCR) assay was utilized for further verification of the action of the WO3NPs on HSV‐1. The cytotoxicity test showed low toxicity (<20%) of the rod‐shaped WO3NPs when they were assayed on Vero cells at concentrations of up to 700 μg/mL. When HSV‐1 was treated with WO3NPs at 700 µg/mL [20% cytotoxicity concentration (CC20); the concentration causing 20% cytotoxicity, ~80% cell viability] and 1000 µg/mL [50% cytotoxicity concentration (CC50); the concentration causing 50% cytotoxicity, ~50% cell viability] for 3 h, the viral load was significantly reduced, achieving inhibition rates of 99.4% and 99.9%, respectively. Additionally, experiments conducted after HSV‐1 infection of Vero cells (post‐treatment assays) indicated that WO3NPs at concentrations of 250, 500, and 750 µg/mL significantly suppressed viral replication, with inhibition rates of 82%, 87.5%, and 96.5%, respectively. WO3NPs have potent inhibitory effects on HSV‐1. Therefore, they can be considered potential candidates for therapeutic development against infections caused by this virus.

Herpes simplex virus (update on dermatologic aspects of sexually transmitted disease and human immunodeficiency virus).

Human papillomavirus is the most common viral sexually transmitted infection worldwide and affects individuals of all ages and both sexes. It is also the most preventable cause of cervical cancer. The World Health Organization’s Cervical Cancer Elimination Strategy (2030 targets) aims for 90% of girls to receive the Human papillomavirus vaccine by age 15, 70% of women to be screened by ages 35–45, and 90% of cervical-cancer cases to be appropriately treated. To determine cervical-cancer–related risk factors and knowledge levels, and to assess Human papillomavirus -related knowledge and attitudes toward vaccination. The survey also examined general adult vaccination behaviors—including measles, influenza, coronavirus, respiratory syncytial virus, and shingles vaccines—among adults. A cross-sectional study was conducted among 1,174 randomly selected adults from Egypt, Syria, Jordan, and Yemen between March and May 2025, using a validated Arabic self-administered questionnaire. Most participants were female (635, 54.2%), university-educated or higher (699, 59.6%), and living in urban areas (796, 67.9%). Regarding risk factors, 489 (41.7%) were smokers, 94 (8.0%) reported genital laser hair removal, 84 (7.2%) had oral or other herpes lesions, and 81 (6.9%) had a family history of reproductive-system cancer. Overall, 626 (53.4%) had poor Human papillomavirus knowledge and 779 (66.5%) had poor cervical-cancer knowledge. Only 60 (9.5%) had ever undergone cervical-cancer screening, and 23 (2.0%) had received at least one Human papillomavirus -vaccine dose. Reported adverse events included allergic reactions (13, 6.8%) and dizziness or fainting (13, 56.5%). Approximately 578 (49.3%) were unaware of the Human papillomavirus vaccine, while 976 (83.3%) had not received—and did not intend to receive—the vaccine, citing lack of information, perceived low risk, adherence to preventive measures, or vaccine unavailability. Most participants demonstrated poor overall knowledge of Human papillomavirus and cervical cancer. Several demographic determinants significantly influenced knowledge and attitudes toward vaccination. Comprehensive health-education initiatives are urgently needed to enhance awareness and progress toward the World Health Organization 2030 elimination targets.

Oral mucositis is one of the most common complications of systemic drug therapy for oncological diseases. With significant severity of its clinical symptoms, dose reduction of medications, changes to their administration schedule, modification of the therapeutic agents used, or complete discontinuation of therapy may be required, which can lead to recurrence of the underlying disease. Treatment of oral mucositis is a complex and not always feasible task. We present a clinical case demonstrating the difficulties of diagnosis and treatment of oral mucositis in a critically ill patient with an oncological disease complicated by pulmonary embolism and sepsis. Oral mucositis developed after an incomplete course of external beam radiation therapy and chemotherapy with temozolomide. The National Cancer Institute Common Toxicity Criteria score at the time of admission to the intensive care unit was 4 points. Ulceration is a common sign of a wide range of oral diseases involving multiple etiological factors that require careful clinical and histopathological diagnosis. The differential diagnosis was carried out with aphthous stomatitis, herpetic gingivostomatitis, oral erythema multiforme, and vesiculobullous lesions of the oral cavity. The severity of clinical manifestations of oral mucositis and periodontitis correlated with the severity of the patient’s critical condition. Nutritional status and the need for nutritional support were determined using the Nutritional Risk Screening-2002 and Modified Nutrition Risk in Critically Ill scores. Mixed nutrition with correction according to protein and energy requirements was used. The presence of oropharyngeal dysphagia necessitated the use of food thickeners, followed by a transition to sip feeding. The maximum possible limitation of mechanical damage and an individually selected hygiene regimen (use of toothpaste with a light gel base and plant components) contributed to the earliest possible recovery of the patient’s oral mucosa. The frequency of oral care was determined daily using the Intensive Care Oral Care Frequency Assessment Scale. Following stabilization of the condition, positive dynamics of the oral mucosa were observed, manifested as a reduction in the severity of xerostomia syndrome by 52% according to The Challacombe Scale of Clinical Oral Dryness. A decrease in the Silness–Loe plaque index from 2 to 0.7 points and in the Muhlemann–Cowell gingival bleeding index from 2.2 to 1 point was recorded. Effective intensive care of oncological disease complications, personalized nutritional support, and an individually selected oral hygiene regimen ensured a favorable outcome of oral mucositis with the possibility of resuming chemotherapy treatment.

The most prevalent viral infection in humans, herpes labialis is caused by the herpes simplex virus 1 (HSV-1). This disease is generally seen in childhood and adolescence. It is a contagious viral infection due to direct contact with active lesions and infected body fluids. It can affect the individuals who are immunocompromised like suffering from Human Immunodeficiency Virus (HIV) infection, undergoing chemotherapy and people who had history of oral herpes. The individuals with exposure to ultraviolet rays, fever, hormonal changes under stress can also become the trigger point for the recurrent infection. The present article reports a case of 60 years old female presented with persistent ulcers on her lower lip for 5 days followed by prodromal symptoms characteristically diagnostic of herpes labialis. She was treated by topical antiviral medication. Treatment is necessary with antiviral drugs therapy for reducing the significant pain and discomfort caused during the infection. Early detection and management is of utmost importance to reduce symptoms and avoid further complications. This case report provides valuable clinical insights into the diagnosis and management of recurrent herpes labialis (RHL), a common but often ignored oral viral condition. Also, it emphasizes the efficacy of topical acyclovir and the supportive role of multivitamin therapy in enhancing immune response and tissue healing.

At present, the choice of material for mucogingival surgery remains an important issue, as the correct selection improves the effectiveness and stability of postoperative outcomes. Although autogenous grafts are considered the gold standard for gingival recession coverage and soft tissue augmentation, they have several drawbacks: limited availability of donor tissue for covering recession, extensive uncontrolled necrosis in the palatal area including the donor site, patient discomfort, and postoperative complications such as painful wounds on the palate, heavy bleeding, postoperative bone exposure, and recurrent herpetic lesions. Due to these significant disadvantages, xenogenic materials have become widely used. The aim of the study was to conduct a comparative analysis of xenogenic collagen materials for soft tissue augmentation and gingival recession coverage, taking into account their advantages and limitations. Material and methods. A systematic review and analysis of literature sources was conducted using foreign and domestic databases over the past 10 years, including Medline (www.ncbi.nlm.nih.gov), the Russian scientific database eLibrary (https://www.elibrary.ru/), and the Cochrane Library (The Cochrane Central Register of Controlled Trials, CENTRAL, www.thecochranelibrary.com). Results and discussion. The literature analysis demonstrated that xenogenic collagen membranes possess several advantages over non-resorbable membranes and autogenous grafts. Unlike non-resorbable materials, the use of resorbable collagen membranes eliminates the potential risks associated with prolonged presence of foreign material and the need for a second surgery to remove it. Compared with autogenous grafts, collagen-based materials are associated with reduced postoperative pain and discomfort, and they are not limited by the size of the donor site. Resorbable collagen membranes offer high biocompatibility and potential biological activity, as well as sufficient plasticity, simplicity, and convenience in clinical application. Conclusion. Currently, the use of resorbable collagen membranes is becoming increasingly widespread and popular. However, further improvements are needed in their properties, particularly in terms of resorption period and stability when exposed in the oral cavity.

Herpes labialis (HL) has been studied very little from a psychological point of view despite its interest as a relatively nonsevere affliction and a cognate disorder to herpes genitalis, that has been studied extensively. The purpose was to study the psychological correlates of HL in several domains so as to establish whether there is a psychological profile characteristic for HL. The subjects were 89 HL patients recruited from three outpatient clinics and 92 controls matched in demographic characteristics to the HL patients. The subjects were administered instruments assessing personality dimensions (the Eysenck Personality Inventory), emotional tendencies (the Profile of Mood States and the Schalling-Sifneos scale of alexithymia) and psychiatric features (the Brief Symptom Inventory by Derogatis). The results showed that HL patients differed from controls in scoring significantly lower on anxiety and psychoticism (each according to two instruments), obsessive-compulsive tendencies, interpersonal sensitivity (inferiority) and alexithymia and in scoring higher on defensiveness, and the emotions of anger, vigor and interest. A discriminant analysis with the psychiatric scales as predictors enabled correct identification of 73% (p &lt; .001) of the subjects. The conclusions are that there is a psychological profile chracteristic of HL, that it differs from that identified for herpes genitalis and that it is characterised by better mental health features than in the controls.

Case Report of Secondary Trigeminal Neuralgia Following Nerve Block-Induced Herpes Zoster Infection.

The herpes simplex virus is a viral pathology, where its transmission occurs through direct exposure to bodily fluids. Herpes simplex virus type 1 (HSV-1) infects orofacial mucosa, resulting in cold sores, while HSV-2 affects genital surfaces, causing genital herpes. Treatment for cold sores usually involves the use of antiviral medications such as acyclovir, to reduce the duration and severity of outbreaks. L-lysine supplementation may help reduce cold sore lesions in patients with recurrent outbreaks. The aim of the present study is to verify the efficacy of the amino acid L-lysine in preventing HSV infection, as well as to evaluate safe doses based on available evidence. For the research, 20 articles related to the topic were selected. Lysine is effective as a daily preventive agent in reducing HSV recurrence and as a therapeutic treatment to decrease the severity and healing time during virus reactivations. Evidence regarding the safety of long-term supplementation with lysine and/or high doses is uncertain for the general population. Doses above 3,000 mg are not recommended due to the risk of kidney damage. Patients with certain health conditions should be closely monitored when taking lysine supplements. Further clinical studies are needed to define recommendations, dosages, and contraindications for this treatment. Key words: Lysine (D008239); Herpes Labialis (D006560); Herpes Simplex (D006561)