Levocetirizine, sold under the brand name Xyzal among others, is a second-generation antihistamine used for the treatment of allergic rhinitis (hay fever) and long term hives of unclear cause. It is less sedating than older antihistamines. It is taken by mouth.Common side effects include sleepiness, dry mouth, cough, vomiting, and diarrhea. Use in pregnancy appears safe but has not been well studied and use when breastfeeding is of unclear safety. It is classified as a second-generation antihistamine and works by blocking histamine H1-receptors.Levocetirizine was approved for medical use in the United States in 2007. It is available as a generic medication. In 2019, it was the 193rd most commonly prescribed medication in the United States, with more than 2 million prescriptions. Medical uses
Levocetirizine is used for allergic rhinitis. This includes allergy symptoms such as watery eyes, runny nose, sneezing, hives, and itching. Side effects
Levocetirizine is referred to as a non-sedating antihistamine as it does not enter the brain in significant amounts and is therefore unlikely to cause drowsiness. Cardiac safety with repolarization may be better than some other antihistamines, as levocetirizine does not significantly prolong the QT interval in healthy individuals. However, some people may still experience some slight sleepiness, headache, mouth dryness, lightheadedness, vision problems (mainly blurred vision), palpitations and fatigue. Pharmacology
Levocetirizine is an antihistamine. It acts as an inverse agonist that decreases activity at histamine H1 receptors.
However, mucosal trauma is thought increase the ability of C. albicans to invade the tissues.Aside from infection and mechanical trauma, inflammatory reactions of the mucosa beneath a denture can also result from irritation or allergy (allergic contact stomatitis) caused by the materials in the denture itself (acrylic, cobalt, chromium), or in response to substances within denture adhesives. Incomplete curing of the acrylic resin (the prosthetic material) may also be an involved factor. Diagnosis
The diagnosis is usually made based upon the clinical appearance, and swabs can be taken of the surface of the denture. Investigations to rule out possibility of diabetes may be indicated. Tissue biopsy is not usually indicated, but if taken shows histologic evidence of proliferative or degenerative responses and reduced keratinization and epithelial atrophy. Classification
The Newton classification divides denture-related stomatitis into three types based on severity. Type one may represent an early stage of the condition, whilst type two is the most common and type three is uncommon. Type 1 - Localized inflammation or pinpoint hyperemia
Type 2 - More diffuse erythema (redness) involving part or all of the mucosa which is covered by the denture
Type 3 - Inflammatory nodular/papillary hyperplasia usually on the central hard palate and the alveolar ridge

Treatment
The most important aspect of treatment is improving denture hygiene, i.e. removing the denture at night, cleaning and disinfecting it, and storing it overnight in an antiseptic solution. This is important as the denture is usually infected with C. albicans which will cause re-infection if it is not removed.