Curious about itch Itch with Common Diagnosis Itch with Uncommon Diagnosis
Mosquito bites are the leading cause of short-term itch and are a common annoyance in the summer months.
These insects feed off the blood of birds and mammals, including humans, and when a mosquito pierces the skin to feed, it leaves behind saliva in the wound. This saliva contains proteins foreign to your body which trigger an immune response, leading to inflammation, redness, swelling, and itching around the bite. The swelling is caused by the release of proinflammatory molecules such as histamine, which promotes blood flow. Histamine also stimulates nearby nerves to transmit itch signals to your spinal cord and brain. Consequently, the severity of your itching from mosquito bites depends on how sensitive your body is to these foreign proteins. In rare cases, individuals allergic to these proteins may develop large local reactions, referred to as Skeeter syndrome, in which extensive hives or other skin rashes may also appear on the skin. However, it is well-appreciated that antihistamines are often not sufficient to treat the swelling and/or itch with mosquito bites. Therefore, it is very likely that there are other factors that also contribute to bite reactions.
While the intense itching from mosquito bites may be irritating, it is normal and typically does not require any treatment. In fact, this itching is part of your body’s natural defense mechanism. Mosquitoes are capable of carrying and transmitting various diseases such as malaria and yellow fever through their saliva. As a result, itch plays an important role in alerting us of their potential danger.
As many as 50 million Americans encounter poison ivy every year. This plant can be found in many parts of the United States and Canada. Poison ivy can be identified by its leaves, which are typically arranged into clusters of three leaflets, leading to the widely-known saying “leaves of three, leave them be”. If you’ve ever encountered poison ivy, you know just how uncomfortable, irritating, and itchy it can be. Here we dive deeper into the science behind how poison ivy causes us to itch.
Poison ivy produces urushiol, an oily substance which can cause an allergic reaction when it comes into contact with your skin. As urushiol enters your skin and interacts with your cells, the immune system recognizes and begins to attack these foreign substances. This response attracts white blood cells to the area and triggers the release of proinflammatory molecules, leading to redness and swelling at the site of contact with poison ivy. Some of these immune molecules also act as a bridge of communication between your immune and nervous systems. These molecules induce itch by binding to your nerves, leading to the transmission of itch signals to the spinal cord and brain, where the sensation of itch is ultimately interpreted. It is well-recognized that to react robustly to poison ivy, one likely has to have encountered it before and become “sensitized”. Therefore, the reaction to poison ivy is very much an allergic hypersensitivity.
Though the itch may be uncomfortable, it usually isn’t dangerous and should resolve within a few weeks without any medical treatment, although remedies such as oatmeal baths, cool compresses, and calamine lotion may help relieve the itching, soreness, and discomfort caused by poison ivy. In severe cases prescription medications such as topical or even oral steroids may be used. There are newer medications that can also be used off-label for this rash and itch.
Bed bugs are one of the most frustrating and uncomfortable pests to deal with in your home. These small, reddish-brown insects feed on human blood and can cause severe and immediate skin issues. They often live in the crevices of mattresses and furniture and may be transported from place to place via clothing or luggage.
Similar to mosquito bites, bed bug bites can cause an allergic reaction in some people, resulting in itchy red welts that may last for days or even weeks. This itching can become quite severe and may even interfere with sleep. However, contrary to bites from other bloodsucking insects, bed bugs frequently display a classic bite pattern in which 3 to 5 bites are arranged in lines or clusters. This is often referred to as a “breakfast, lunch, and dinner” pattern. Bed bugs generally feed on exposed surfaces like the arms and legs and bites are often noticed upon waking as these bugs are most active at night.
While bed bug bites don’t require medical treatment in most people, an important step in preventing these bites is eradicating the bed bugs from your home once identified via professional pest control services. Bed bugs do not live on your body, however, it is highly recommended that all clothing and sheets be washed and dried in high heat. Luggage should be removed from the living premises for an extended period of time.
The thought of having scabies can be confusing. What does this mean?
Scabies is an itchy skin condition that is caused by tiny mites that burrow under the surface of the skin. It is highly contagious and can spread easily through close contact with someone who has scabies or by sharing personal items such as bedding, towels, or clothing. Scabies can cause intense itching along with a pimple-like rash or sometimes thin gray lines on the skin where the mites have burrowed. This itching is caused by the body’s allergic reaction to the mites, as well as their eggs and waste. Scabies, in contrast to bed bugs, live in your skin. Therefore, the only way to get rid of them is to be treated with an anti-parasitic medication.
The best way to treat scabies is with prescription medications such as permethrin cream or oral ivermectin. These medications are usually applied over the body from neck to toes. To prevent reinfection, all household members should ideally be treated at the same time. In addition to treating active infestations, all linens and clothing should be laundered thoroughly in hot washing and drying cycles.
Itch is a sensation that many people experience yet don’t understand. The philosopher Aristotle (384-322 BC) recorded one of the first known descriptions of itch, characterizing how animals scratch themselves in a manner similar to modern humans.