Author: Dr Eugene Tan, Dermatology Registrar, Waikato Hospital, Hamilton, New Zealand, 2009.
Helicobater pylori (H. pylori) is a bacterium that is found in the stomach and is responsible for most cases of peptic ulcer. About half of the world's population has this bacteria making it the most common bacterial infection in humans .
H. pylori is more common in developing nations. The risk of contracting H. pylori is related to socioeconomic status and poor living conditions such as overcrowding,lack of clean, running water and a higher number of siblings. As a result, most children in developing nations are infected before the age of 10.
In New Zealand, a higher prevalence is noted amongst Maori and Polynesians. Studies show that about 5% of European children become infected by the age of 20 years, in contrast to 50% of Polynesian children .
The exact route of infection remains unknown but person-to-person transmission through oral/oral or faecal/oral exposure is the most likely cause. This means that activities such as sharing food, cutlery or poor toilet hygiene can result in transmission of H. pylori to another individual.
H. pylori causes direct disease of the stomach. Other diseases are probably related to the body's immune response to the bacteria.
Most individuals with H. pylori infection have no symptoms. Symptoms arise if infection with H. pylori causes peptic ulcers or gastritis. These symptoms can be non-specific and range from:
The damage to the lining of the stomach is due to a complex interaction of the bacteria and the host's immune response. H. pylori releases several enzymes and microbial products that directly damage the lining of the stomach. The immune system reacts by mounting a florid inflammatory response in an attempt to eradicate the bacteria. As a consequence of this inflammatory response, the stomach lining is unintentionally damaged.
There are several tests available to detect the presence of H. pylori in the stomach:
Blood test and breath test are often the first line approach to testing for H. pylori. Endoscopic biopsy is a relatively invasive procedure and is often reserved for patients who require endoscopy for another reason.
The American College of Gastroenterology recommends testing in the following situations :
Testing is not recommended for people who are asymptomatic (no symptoms) or who have no past history of peptic ulcer disease. However, certain population groups who are at risk for developing ulcers or stomach cancers may be considered for asymptomatic testing.
Treatment of H. pylori infection involves taking several medications for 7 to 14 days (“Triple therapy”), eg, a proton-pump inhibitor (inhibitor of stomach acid secretion) such as omeprazole 40mg once daily, amoxicillin 1g twice daily and clarithromycin 500mg twice daily.
Treatment cures up to 90% of individuals.
H. pylori has been implicated in a variety of diseases that are not related to the gastrointestinal tract. The skin is an example and several studies have suggested an association with the following conditions [4,5]:
Several small studies have suggested that eradicating H. pylori has a positive outcome on certain skin diseases such as chronic urticaria, Behcet disease, lichen planus, atopic dermatitis, Sweet disease and systemic sclerosis. Conditions which may not benefit are psoriasis and rosacea.
These studies are not randomised and involve small numbers of patients so no definitive conclusion can be drawn about the eradication of H. pylori in skin diseases at present.
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