Daltonism: Colorblindness of the red-green type (also known as deuteranopia or deuteranomaly).
The term “Daltonism” is derived from the name of the chemist and physicist, John Dalton (1766-1844). Dalton was born in a village in Cumberland, England where his father, Joseph, was a weaver in poor circumstances. He was educated by his father and John Fletcher, teacher in a Quaker school. When Fletcher retired in 1778, Dalton took his place. In 1793 he was appointed teacher of mathematics and natural philosophy at New College in Manchester. In 1803 he put forth the facts embodied in his law of partial pressures: the pressure of a mixture of gases is the sum of the pressures which would be exerted separately by the several constituents if each alone were present. Dalton’s reputation largely rests upon his great Atomic Theory. It was said of Dalton that “into society he rarely went, and his only amusement was a game of bowls on Thursday afternoons.”
Dalton described his and his brother’s affliction of colorblindness with defective perception of red and green in the first scientific paper he published. It was entitled “Extraordinary facts relating to the vision of colours, with observation” (Mem Literary Philos Soc Manchester 5: 28-45, 1798). It is the first recognized account of red-green colorblindness.
- Dancing mania of Maracaibo
Dancing mania of Maracaibo: Huntington disease. Beginning in the 1950s Dr. Americo Negrette observed a number of people with a dancing mania in villages along Lake Maracaibo, Venezuela. The syndrome was then called el mal (the bad) or el mal de San Vito (the sickness of Saint Vitus). Dr. Negrette diagnosed and reclassified the dancing […]
Dander: Tiny scales shed from human or animal skin or hair. Dander floats in the air, settles on surfaces, and makes up a good portion of household dust. Cat dander is a common cause of allergic reactions.
Dandruff: A scalp condition that produces white flakes that may be shed and fall from the hair. One cause of dandruff is overworking of the sebaceous glands. Another cause of dandruff is fungus, especially an abundance of the fungus Pitrosporum ovale. If several weeks of using a good-quality shampoo does not stop the dandruff, treatment […]
- Dandy fever
Dandy fever: An acute mosquito- borne viral illness of sudden onset that usually follows a benign course with headache, fever, prostration, severe joint and muscle pain, swollen glands (lymphadenopathy) and rash. The presence (the “dengue triad”) of fever, rash, and headache (and other pains) is particularly characteristic. Better known as dengue, the disease is endemic […]
- Danlos syndrome
Danlos syndrome: Better known as Ehlers-Danlos syndrome (EDS), is an inherited disorder with easy bruising, joint hypermobility (loose joints), skin laxity, and weakness of tissues. There are a number of different Ehlers-Danlos syndromes which share these features but can be categorized into nine different types. Type I EDS (the “gravis” form od EDS) is characterized […]