An introduction to the causes of hives
There are multiple causes of hives, but most often an outbreak is related to a flare-up of the inflammatory chemical histamine in your immune system.
This can connect the skin condition to various causal factors like allergies, a weakened immune system or certain types of medication.
It is important to have an idea of what is triggering this affliction as it can help you take preventative measures against an unpleasant outburst in the future.
Allergies
Hives often appear after your skin has come into contact with an allergic substance, such as pollen, stinging nettles or some types of food.
When your immune system recognises these elements as being potential harmful, it will release a wave of inflammatory chemicals to attack the potential irritant and to heal the affected area.
Hives often manifest as a result of this chemical reaction, as histamine dilates the blood vessels to allow a greater flow of nutrients to the affected area.
Occasionally, this can cause blood to leak out the vessels and into the surrounding skin tissue, leading to the appearance of hives.
Genetics
There are certain genetic factors that can make you more predisposed to developing certain variants of hives. Cold hives, for example, are hives that occur when you come into contact with extremely low temperatures.
A report has detailed that the PLCG2 gene can be involved with the function of an important enzyme, PLC-gamma-2, which often controls the behaviour of certain immune cells, making you more susceptible to cold hives.1
It’s also believed that there are various other types of hives that might be genetically influenced in this way so it might be worth consulting other members of your family to see if they have ever suffered from the condition.
1http://www.medpagetoday.com/allergyimmunology/allergy/30615
Weak immune system
Chronic hives often appear as a result of an underlying health condition, like thyroid issues or because your immune system more vulnerable, such as in cases of a blood transfusion or a viral infection like the cold.
When your immune system is weak or immature, it can become hyperactive and overworked, more sensitive to irritants and more prone to identifying harmless cells as pathogens.
This state of stress can cause a wave of inflammatory chemicals to be released, relaxing the blood vessels and making it easier for blood plasma to find its way into the surrounding tissues, triggering a flare-up of hive.
There is even some evidence to suggest that in some cases of hives, the immune system itself might be the main perpetrator, instigating an autoimmune reaction where the body starts to attack healthy cells.2
2http://www.worldallergy.org/public/allergic_diseases_center/urticaria/urticaria.php
Poor nutrition
When it comes to supporting your immune system, there’s no greater asset than your diet, which is why a poor nutrition can have such a destabilising effect on your immune system.
If your diet is high in acidic foods, refined sugars and caffeine, it can inspire the release of inflammatory chemicals, such as adrenalin or histamine.
When these are released, they can upset your hive symptoms and exhaust your immune cells, eventually causing them to become either hyperactive or sluggish.
Alcohol has also been linked to the progression of hives, as it can increase your body temperature and make you sweat more, putting you at risk of developing cholinergic hives.3
It’s also important to watch what you eat if you are allergic to any food products, as these can trigger an episode of hives as well as angioedema.
3http://www.dermnetnz.org/topics/cholinergic-urticaria/
Stress
The link between stress and hives has been much discussed, with Stress Hives, even being acknowledged as a known subtype of the condition.
This can be because of your immune system’s response to emotional distress as it will often inspire your ‘fight or flight’ reflexes, affecting your sympathetic nervous system.
Your immune system will release a wave of inflammatory chemicals to dilate your blood vessels and increase your heart-rate as it anticipates that your body will be involved in vigorous physical activity.
This can cause you to sweat more, raise your body temperature and irritate any existing symptoms, making you more vulnerable to an outbreak of ‘stress hives.’
H. Pylori bacteria
H. Pylori bacteria, or Helicobacter pylori, is the most common cause of bacterial infections worldwide and has been linked to outbreaks of chronic hives.
H. Pylori can weaken the lining of the stomach, affecting the digestion of your food and increase your susceptibility to any allergens that may appear in your digestive tract.4
The immune system can also play a role as the bacteria can inspire the release of inflammatory chemicals, worsening your existing symptoms and making you more exposed to inflammation and irritation.
4http://www.ncbi.nlm.nih.gov/pubmed/15881645
Exposure
The environment that you inhabit can also play a role in making you more susceptible to an outbreak of hives. Conditions of extreme heat, low humidity or exposure to the cold or UV radiation can affect your skin, stimulating a release of inflammatory chemicals and giving rise to episodes of either cholinergic hives or cold hives.5
Cholinergic hives do not tend to last for a protracted period of time and can be caused by excessive heat and sweating. In these instances, your skin and your body will often become dehydrated, affecting your blood circulation and digestion, preventing toxins from being flushed from the body and keeping the blood vessels dilated.
Cold hives are less common but can appear as a result of being exposed to extreme colds, such as swimming in icy water or facing frigid winter winds. The immune system stimulates a ‘flight or fight’ reaction and inflammatory chemicals are released in order to increase your chances of survival.
5http://patient.info/health/physical-urticarias-hives
Insect bites
If you’ve ever been bitten by a mosquito or ravaged by midges, then you are probably aware of how your skin can react to insect bites.
In some instances, especially in the case of mosquito bites, your immune system will recognise the proteins in the insect saliva as being harmful and trigger an immune response to kill the harmful pathogens.
This can cause skin discolouration, inflammation and a range of other unpleasant symptoms, including the appearance of hives.
Medication
It can be rare, but it is known that certain types of medication can make you more predisposed towards suffering from hives.
Ordinary painkillers like aspirin, antibiotics and certain types of blood-pressure can react negatively with your immune system, stimulating an outbreak of hives.
This is because it type of medicine contains a make-up of chemicals, some of which can trigger an inflammatory response from the immune system, or even make it more vulnerable and sensitive to skin conditions and infections.
