Muddy-brown pigmentation on the cheeks or elsewhere on the face that develops in about half of all women during pregnancy. Some women also develop it outside pregnancy, as do some women on hormone therapy. The pigmentation is worsened by ultraviolet (UV) light, which tends to darken it. Regular use of a broad-spectrum sunscreen against both UVA and UVB can prevent progression of the condition. The hyperpigmentation (excess pigment in the skin) usually lightens up with the use of topical treatment with bleaching agents, together with the topical application of retinoin (vitamin A acid, Retin-A). Light chemical peels can also aid and abet the effects of the topical therapy. Also known as melasma or chloasma.
- Mask, oxygen
A mask that covers the mouth and nose, and is hooked up to an oxygen tank. It delivers oxygen directly to the patient. Oxygen can also be delivered directly through a nasal catheter, a tube that divides into two smaller tubes that go into the nostrils.
- Masklike face
An expressionless face with little or no sense of animation; a face that is more like a mask than a normal face. Masklike face is seen in a number of disorders, including Parkinson’s disease and myotonic dystrophy. Also known as masklike facies.
The derivation of pleasure from one’s own pain. Masochism is considered a sexual disorder (paraphilia). Named after the 19th-century Austrian writer Leopold von Sacher-Masoch.
- MASS syndrome
A heritable disorder of connective tissue characterized by involvement of the mitral valve, aorta, skeleton, and skin. Hence, the acronym MASS (Mitral valve, Aorta, Skeleton, Skin). The MASS syndrome is due to a mutation in FBN1, the fibrillin 1 gene. The same gene as is mutated in Marfan syndrome.
The therapeutic practice of manipulating the muscles and limbs to ease tension and reduce pain. Massage can be a part of physical therapy or practiced on its own. It can be effective for reducing the symptoms of disorders of or pain in the muscles and nervous system, and it is often used to reduce stress.