What's the difference between discoloration and melasma?
Discoloration
Definition:
(n.) The act of discoloring, or the state of being discolored; alteration of hue or appearance.
(n.) A discolored spot; a stain.
Example Sentences:
(1) Discoloration and pulpal obliteration were the major manifestations.
(2) The etched porcelain laminate veneer is a new conservative treatment that offers a solution to fractured, discolored, and worn anterior teeth.
(3) In a relative safe way many types of discoloration can be treated.
(4) Treatment did not influence total or percent discolored areas.
(5) After 24 h, the extensor digitorum longus and tibialis anterior muscles appeared grossly swollen (edematous) and discolored.
(6) Scar tissue and leukoderma-type discoloration of the skin due to deep burns are treated by dermabrasion and thin split-thickness skin-graft application.
(7) The test strips are not absolutely yeastspecific, since problem organisms and molds may cause a brown discoloration.
(8) Interest in the use of bleaching for treatment of discolored teeth is increasing.
(9) The discolored area had enlarged during a recent pregnancy, contained multiple subcutaneous nodules, demonstrated increased cellularity and mitotic activity, and was associated with an axillary lymph node containing black streaks within the capsule.
(10) Subjects who developed dark brownish discoloration on the facial surfaces of their anterior teeth during a 3-week period following professional cleaning of the teeth were selected for study.
(11) The hearts of these rats were enlarged and discolored.
(12) The surgical procedure consisted of debriding muscle tissue which showed impaired contractility, consistency, discoloration or lack of capillary bleeding--current criteria of non-viability.
(13) The second group included generally younger patients (average age 2.9 years) in whom misformulation of rifampicin preparations for treatment of Haemophilus influenzae Type B resulted in bright reddish-orange discoloration to the skin.
(14) Circumpulpal discoloration commenced on the sixth day postmortem and increased to 18 days.
(15) A yellow compound was isolated from commercially available, discolored, polyethylene ophthalmic closures containing titanium dioxide and butylated hydroxytoluene (I).
(16) A weak chelator did not alter the discoloration tendency.
(17) Five patients are reported in whom brownish grey discoloration occurred on the light-exposed parts of the dermis after long-term amiodarone-medication.
(18) Chicks exhibited cerebellar and cerebral encephalitis characterized by brown-red discoloration of affected brain tissue.
(19) The risk factors studied included: donor parameters (age, sex, cause of death, haemodynamic parameters and renal function); retrieval parameters (kidney alone or multiorgan harvesting, discoloration and renal perfusion quality); organ characteristics (multiple arteries and cold ischemia time); recipients parameters (age, sex, prior transplantation, local transplantation or not, and HLA matching).
(20) With the breakdown of trapped hemoglobin, iron-containing hemosiderin is stored in synovial tissue producing rusty discoloration and proliferative reaction.
Melasma
Definition:
(n.) A dark discoloration of the skin, usually local; as, Addison's melasma, or Addison's disease.
Example Sentences:
(1) Thus, topical azelaic acid, employed either as monotherapy or in combination with other treatments, is likely to prove of value in the management of acne and several hyperpigmentary disorders, most notably melasma.
(2) This study demonstrated that melasma in men shares the same clinicohistologic characteristics as in women, but hormonal factors do not seem to play major significant role.
(3) Clinical trials with various depigmenting formulations containing hydroquinone were conducted to determine the ideal concentration of hydroquinone, retinoic acid, and corticosteroids for the treatment of melasma.
(4) Regarding the origin of the melasma, it was found that 70% of women who developed melasma during pregnancy or while using oral contraceptives had thyroid abnormalities compared to 39.4% of patients with idiopathic melasma.
(5) Particularly important is its action on abnormal melanocytes, which has led to the possibility of obtaining good results on melasma and highly durable therapeutic responses on lentigo maligna.
(6) In subgroups of the total number of pregnant women, with similar proportion of patients with placebo and sunscreen, the melasma appearances were significantly lower in skin types I-II, and in those that used cosmetics (versus those that did not).
(7) Melasma most often appears 1-4 months after taking the pill.
(8) It is suggested that actinic lichen planus be considered in the differential diagnosis of melasma.
(9) In 30 patients "with optimum fulfillment" in the products application (16 with placebo and 14 with sunscreen cream) the melasma appearances were significantly lower in those with sunscreen application.
(10) The differential diagnosis includes melasma and facial erythema ab igne (local cooks).
(11) Melasma is localized hyperpigmentation over the forehead, upper lips, cheeks, and chin.
(12) Melasma is a macular hypermelanosis of the sun-exposed areas of the face and neck.
(13) The monobenzyl ether of hydroquinone should never be used in melasma therapy.
(14) Hormonal alterations contribute to the physiologic skin changes in pregnancy, which include hyperpigmentation and melasma, striae gravidarum and vascular phenomena, such as spiders, palmar erythema and varicosities.
(15) Less commonly, discrete and confluent papules and hypermelanotic patches, sometimes assuming a melasma-like appearance, were present.
(17) Based on the results of the trials and our earlier clinical experience, we conclude that treatment of melasma should involve the following: avoidance of sun exposure, constant use of broad-spectrum sunscreens, and topical application of a cream or lotion containing 2% hydroquinone and 0.05% to 0.1% retinoic acid (tretinoin).
(18) In this study, evidence suggesting an association between autoimmune thyroid disorders and melasma and the relationship of thyroid disorders to the origin of melasma is presented.
(19) Based on the inhibitor constant on tyrosinase, at least cytotoxic levels of azelaic acid would be required for the direct inhibition of melanin biosynthesis in melanosomes if this mechanism is responsible for depigmentation in the hyperpigmentation disorders lentigo maligna and melasma.
(20) In controlled studies, topical azelaic acid demonstrated comparable anti-acne efficacy to topical tretinoin, benzoyl peroxide, erythromycin and oral tetracycline, while in patients with melasma azelaic acid proved at least as effective as topical hydroquinone.