Polycythemia veraIn oncology, polycythemia vera (PV) is an uncommon myeloproliferative neoplasm in which the bone marrow makes too many red blood cells. Approximately 98% of PV patients have a JAK2 gene mutation in their blood-forming cells (compared with 0.1-0.2% of the general population). Most of the health concerns associated with PV, such as thrombosis, are caused by the blood being thicker as a result of the increased red blood cells. PV may be asymptomatic.
Atopic dermatitisAtopic dermatitis (AD), also known as atopic eczema, is chronic type of inflammation of the skin. Atopic dermatitis is also often called simply eczema, but "eczema" is also used to refer to dermatitis, the larger group of skin conditions. Atopic dermatitis results in itchy, red, swollen, and cracked skin. Clear fluid may come from the affected areas, which can thicken over time. The thickening phenomenon is known as lichenification.
Scratch reflexThe scratch reflex is an automatic response to the activation of sensory neurons located on the surface of the body. Sensory neurons can be activated via stimulation, such as a parasite on the body, but can also be activated by responding to a chemical stimulus that produces an itching sensation. During a scratch reflex, a limb reaches toward and rubs against the site on the body surface that has been stimulated.
ScabiesScabies (, SKAY-beez; also sometimes known as the seven-year itch) is a contagious human skin infestation by the tiny (0.2–0.45 mm) mite Sarcoptes scabiei, variety hominis. The word is from Latin: scabere, lit. 'to scratch'. It is a particular public health problem in crowded settings such as care homes, schools, refugee camps, prisons, and hospitals. The most common symptoms are severe itchiness and a pimple-like rash.
PainPain is a distressing bodily feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotionalexperience associated with, or resembling that associated with, actual or potential tissue damage." Pain motivates animals to withdraw from damaging situations, to protect a damaged body part while it heals, and to avoid similar experiences in the future.
Chronic conditionA chronic condition, also known as a chronic disease or chronic illness, is a health condition or disease that is persistent or otherwise long-lasting in its effects. The term chronic is often applied when the course of the disease lasts for more than three months.Withdrawal reflexThe withdrawal reflex (nociceptive flexion reflex or flexor withdrawal reflex) is a spinal reflex intended to protect the body from damaging stimuli. The reflex rapidly coordinates the contractions of all the flexor muscles and the relaxations of the extensors in that limb causing sudden withdrawal from the potentially damaging stimulus. Spinal reflexes are often monosynaptic and are mediated by a simple reflex arc.
SkinSkin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different developmental origin, structure and chemical composition. The adjective cutaneous means "of the skin" (from Latin cutis 'skin').
Spinothalamic tractThe spinothalamic tract is a nerve tract in the anterolateral system in the spinal cord. This tract is an ascending sensory pathway to the thalamus. From the ventral posterolateral nucleus in the thalamus, sensory information is relayed upward to the somatosensory cortex of the postcentral gyrus. The spinothalamic tract consists of two adjacent pathways: anterior and lateral. The anterior spinothalamic tract carries information about crude touch.
NerveA nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system.*As an Amazon Associate I earn from qualifying purchases.