EVER WONDERED WHAT ARE COLD SORES?
Frequent outbreak of herpes labialis can affect quality of life by prodromes like burning, itching, and swelling. Topical applied preparations aim to shorten the duration of symptoms, inhibit the virus replication and/or accelerate the healing process. Local concentrated heat (LCH) can reduce burning, itching, or swelling of the skin by influence of mechano-heat sensitive afferent neurons.
Cold sores are primarily caused by infections of herpes simplex virus type 1 (HSV-1), which has a seroprevalence of 90% within the adult population in UK. HSV-1 is a member of the virus subfamily of α-Herpesviridae. The virions consist of nucleocapsid, tegument, and a lipid envelope originated from the host cell with embedded virus-encoded glycoproteins at the surface.
In addition to a total of 30 viral proteins the virions contain also cellular proteins (eg, heat shock protein [HSP] and actin). The viral replication cycle has several phases. After the virions are absorbed in the target cell they bind to structures of the cellular surface (eg, carbohydrate polymers and protein receptors) via glycoproteins and the envelope merges with the cell membrane.
After the liberation of the nucleocapsid into the cytoplasm and its migration to the nuclear pores via microtubules, the viral genomic deoxyribonucleic acid (DNA) infiltrates the nucleus and circulates. Through cascading expression of different gene groups the virus genome finally replicates together with other virus components into cell vesicles.
Merging with the cell membrane the fully developed virus particle is released. Aberrant, non- infectious virus particles are distinguished from fully developed, infectious virions.
Virions have the ability to remain in a state of latency in specific target cells. Different internal (eg, stress and immunosuppression) or external (eg, ultraviolet [UV] light and hormones) factors can trigger the reactivation.
TRIGGER FACTORS FOR COLD SORES
- UV Radiation
- Week Immune System
- Hormonal Fluctuations
The Real Life Test
To examine the effectiveness of two different topical applications (LCH versus topical acyclovir [TACV]) under real-life conditions, we conducted a prospective, observational, reference-controlled cohort pilot study with 103 patients. The occurrence of prodromal burning, itching, swelling, and quality of life were assessed.
Wondering, how did we do it?
This non-interventional pilot study (NIS) (J. Wohlrab et al. in Clinical, Cosmetic and Investigational Dermatology 2013:6) was conducted between April and November 2012 in collaboration with eleven pharmacies in Germany. The study had been approved by the ethics committee of the University of Greifswald, registered at German authorities and at “German Register for Clinical Studies”
The research was designed as a prospective, reference controlled, observational cohort study with 103 patients to describe the symptomatic outcomes after use of local concentrated heat (LCH) or a topical acyclovir (TACV) treatment.
For application of LCH, a CE-certified medical device of class 2A (Herpotherm®) with a guaranteed duration-heat-constant was used, which is intended for non-invasive administration onto the skin. The LCH device produces a microchip controlled concentrated thermal impulse of 50°C–53°C on a 38.5 mm² covered plate for 4 seconds.
The NIS was patient-initiated, and involved the self-application under real life conditions.
What Were The Results?
Patients in need for treatment who bought either a TACV or a LCH device were asked by the pharmacist to participate in the study. The majority (63%) of the patients had used TACV in the past, only 3% of the patients had been aware of LCH as an alternative therapy.
After the pharmacist informed the patient about the aim of the study, the patient was asked to sign the informed consent form. There was no selection of subjects to one or another observation group (OG). TACV and LCH were applied according to the instructions in the summary of product characteristics (SPC). TACV: 5 times per day for 5 days; LCH maximum of 5 times per day until symptoms disappeared.
- 50% reduction in Symptoms and condition during day 2- 3 (Herpotherm V/S Aciclovir)
- The LCH observation group (OG) showed a significantly faster improvement in all symptoms after 1-day of application than the TACV OG. The burden and duration of disease was lower and shorter in the LCH OG than in the TACV OG.
The success of treatment with HERPOtherm was described as very good by 53% of the patients, whereas only 12% described the success of aciclovir application as very good.
The prodromal symptoms in recurrent cold sores were attenuated more effectively by local concentrated heat than by topical acyclovir.