Related topics: bees

The Hong Kong beekeeper harvesting hives barehanded

High up in the hills above Hong Kong, Yip Ki-hok uses nothing but his bare hands to remove a honey-filled nest of swarming bees—a remarkable skill he learned after the hardship of China's famine years.

Using artificial intelligence to save bees

A beekeeper teamed up with the Signal Processing Laboratory 5 and a group of EPFL students to develop an app that counts the number of Varroa mites in beehives. This parasite is one of the two main threats – along with ...

The farmer wants a hive—inside the world of renting bees

Almonds, blueberries, apples, melons – all of these fruits, and many more, rely on insect pollination. Some crops rely more on pollinators than others. Insect pollination isn't just about the number of fruits produced – ...

Pesticides used to help bees may actually harm them

Pesticides beekeepers are using to improve honeybee health may actually be harming the bees by damaging the bacteria communities in their guts, according to a team led by a Virginia Tech scientist.

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Urticaria

Urticaria (from the Latin urtica, nettle (whence It. ortica, Sp. ortiga, Pg. urtiga, Fr. ortie) urere, to burn) (or hives) is a kind of skin rash notable for pale red, raised, itchy bumps. Hives is frequently caused by allergic reactions; however, there are many non-allergic causes. Most cases of hives lasting less than six weeks (acute urticaria) are the result of an allergic trigger. Chronic urticaria (hives lasting longer than six weeks) is rarely due to an allergy. The majority of patients with chronic hives have an unknown (idiopathic) cause. Perhaps as many as 30–40% of patients with chronic idiopathic urticaria will, in fact, have an autoimmune cause. Acute viral infection is another common cause of acute urticaria (viral exanthem). Less common causes of hives include friction, pressure, temperature extremes, exercise, and sunlight.

Weals (raised areas surrounded by a red base) from urticaria can appear anywhere on the surface of the skin. Whether the trigger is allergic or non-allergic, there is a complex release of inflammatory mediators, including histamine from cutaneous mast cells, resulting in fluid leakage from superficial blood vessels. Wheals may be pinpoint in size, or several inches in diameter. Angioedema is a related condition (also from allergic and non-allergic causes), though fluid leakage is from much deeper blood vessels. Individual hives that are painful, last more than 24 hours, or leave a bruise as they heal are more likely to be a more serious condition called urticarial vasculitis. Hives caused by stroking the skin (often linear in appearance) are due to a benign condition called dermographism.

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