Melanosis

There is a bath PUVA and an oral PUVA. Bath PUVA therapies involve soaking in a bath of psoralens liquid for 15 minutes prior to UVA treatment. Oral PUVA involves taking an oral psoralens capsule the day prior to a UVA treatment. Oral psoralens such as methoxsalen cause nausea in many patients. Other adverse effects of PUVA include photosensitivity, which necessitates the use of eye protection and UVA-blocking sunscreen for 24 hours after a PUVA treatment macular melanosis at exposed sites (PUVA lentigines) and increased risk of skin cancers, especially squamous cell carcinoma.21... 

Lentigines Plural of lentigo, which is a small, flat, tan to dark brown or black, macular melanosis on the skin that looks like a freckle but is histologically distinct. Lentigines do not darken on exposure to sunlight, freckles do. 

Melanosis Excessive pigmentation of the skin due to a disturbance in melanin pigmentation also called melanism. 

Klein-Szanto, A., Bradl, M., Porter, S., and Mintz, B. (1991). Melanosis and associated tumors in transgenic mice. F roc. Natl. Acad. Sci. USA 88 169-173. 

Soluble inorganic arsenic is acutely toxic, and ingestion of large doses leads to gastrointestinal symptoms, disturbances of cardiovascular and nervous system functions, and eventually death. In survivors, bone marrow depression, haemolysis, hepatomegaly, melanosis, polyneuropathy, and encephalopathy may be observed. 

Melanosis coll Melanosis coll is a darkened pigmentation of the colonic mucosa resulting from chronic use of anthraquinone derivatives (casanthrol, cascara sagrada, senna). 

Aloe, senna, and cascara occur naturally in plants. These laxatives are poorly absorbed and after hydrolysis in the colon, produce a bowel movement in 6-12 hours when given orally and within 2 hours when given rectally. Chronic use leads to a characteristic brown pigmentation of the colon known as melanosis coli. There has been some concern that these agents may be carcinogenic, but epidemiologic studies do not suggest a relation to colorectal cancer. 

Irradiation of the substrate, 3,4-dihydroxyphenylalanine, accelerated the reaction. Therefore the alteration of substrate by irradiation was not found to be responsible for the decrease in melanosis observed in fresh shrimp. 

Reports indicated that the phenolase responsible for melanogenesis of shrimp was located in the shell and concentrated primarily at the joints between segments. It was concluded that water and oxygen may diffuse through these joints, and that their radiolysis products were responsible for the inactivation of phenolase and subsequent reduction of melanosis. 

It was ultimately concluded that low-dose gamma irradiation of fresh shrimp reduced melanosis and resulted in a significant extension of their iced-storage life. However, if shrimp were held beyond the onset of melanogenesis, subsequent low-dose irradiation accelerated blackspot formation, which reduced consumer appeal, and therefore was definitely undesirable (3,13). 

In beagle dogs, intravenously injected radium-226 was deposited in the melanin granules of pigmented cells and rodlike organelles of the tapetum in the eye (a structure that humans do not have). Retention in the eye varied inversely with dose. At doses from 0.062 to 1.1 pCi/kg (2.3 to 41 kBq/kg), loss of pigment at the higher doses and melanosis and intraocular melanoma formation at the lower doses were observed (Taylor et al. 1972). 

Senna may cause abdominal cramps and diarrhoea. Prolonged use of senna may produce watery diarrhoea with excessive loss of fluid and electrolytes, particularly potassium, muscular weakness and weight loss. Changes in the intestinal musculature associated with malabsorption and dilation of the bowel, similar to ulcerative colitis and to megacolon, may also occur. Cardiac and renal symptoms have been reported. Melanosis coli and a red or yellow discoloration of the urine and faeces may also occur. 

Many skin reactions have been reported with neuroleptic drugs, including urticaria, abscesses after intramuscular injection, rashes, photosensitivity or exaggerated sunburn, contact dermatitis, and melanosis or blue-gray skin discoloration. Skin rashes are usually benign. Chlorpromazine is most often implicated (incidence 5-10%). 

The toxicity, health effects, and related symptoms of poisoning caused by different metals and metal compounds in humans is modulated by many factors. In a large number of instances, poisoning from metal compounds is because of the persistence of the metal dusts and fumes present in the workplace, as well as the properties of each metal, the pattern or route of exposure, the form and nature of the metal, and the quantity or concentration of the metal compound ingested, inhaled, or absorbed into the system. The health status of a worker modulates its toxicity. Toxic metals cause severe poisoning and skin diseases such as melanosis, leukomelanosis, keratosis, nonpitting edema, gangrene, and skin cancer. 

GI pain and bleeding pulmonary edema anemia, destruction of red blood cells liver necrosis, kidney failure encephalopathy and other central and peripheral nervous system disorders. Chronic toxicity can lead to systemic hypotension skin disorders such as eczema, hyperkeratosis, melanosis, ulceration, skin cancers blood problems such as anemia, acute leukemia kidney failure delirium, encephalopathy, seizures, neuropathy. 

Patients taking some anthraquinones may notice their urine coloured brown (if acid) or red (if alkaline). Prolonged use can cause melanosis of the colon. 

Zolog N, Leibovici M. La melanose conjonctivale par epinephrine. [Conjunctival melanosis caused by epinephrine.) BnU Mem Soc Fr Ophtalmol 1973 86(0) 198-200. 

Melanosis coli occurred in a 39-year-old liver transplant patient who took an over-the-counter product containing aloe, rheum, and frangula (4). The typical brownish pigmentation of the colonic mucosa developed over 10 months. The medication was withdrawn and follow-up colonoscopy 1 year later showed normal looking mucosa. However, a sessile polypoid lesion was found in the transverse colon. Histology showed tubulovillous adenoma with extensive low-grade dysplasia. 

Willems M, van Butrren HR, de Krijger R. Anthranoid self-medication catrsing rapid development of melanosis coli. Neth J Med 2003 61(l) 22-4. 

The safety and efficacy of senna have been reviewed (4). Its rhein-anthrone-induced laxative effects occur through two distinct mechanisms, an increase in intestinal fluid transport, which causes accumulation of fluid intralumm-ally, and an increase in intestinal motihty. Senna can cause mild abdominal complaints, such as cramps or pain. Other adverse effects are discoloration of the urine and hemorrhoidal congestion. Prolonged use and overdose can result in diarrhea, extreme loss of electrolytes, especially potassium, damage to the surface epithelium, and impairment of bowel function by damage to autonomic nerves. Abuse of senna has also been associated with melanosis coli, but resolution occurs 8-11 months after withdrawal. Tolerance and genotoxicity do not seem to be problems associated with senna, especially when used periodically in therapeutic doses. 

Hirasaki S, Koide N, Ogawa H, Ujike K, Okada H, Mizuno M, Ukida M, Tsuji T. A case of melanosis duodeni alleviated by the discontinuation of ferrous sulfite. Dig Endosc 1998 10 55-60. 

All of the anthraquinones can cause cramping and abdominal discomfort. Chronic use can be associated with melanosis coU. The urine can be colored red. The possibihty of colonic injury has been discussed (see General adverse effects of laxatives in this monograph). Hepatitis, confirmed by rechallenge, has been reported, possibly due to re-absorption of rhein anthron produced in the intestine (SEDA-16, 425). 

The skin also appears to be a critical target of arsenic toxicity. Dermatitis is observed with erythema followed by itching and swelling with a mottled appearance. Melanosis (abnormal pigmentation) subsequently appears at various points on the body often followed by hyperkeratosis (thickening of the skin). 

Acute exposure of quinone leads to dermatitis, hypo-melanosis, and delayed hyperpigmentation. It is a skin irritant, which may cause redness, swelling, and necrosis. 

Hexopar inositol nicotinate nicotinic acid, hexoprenaline [ban, inn] (hexoprenaline hydrochloride [jan]) is a P-ADRENOCEPTOR agonist selective for the P2-subtype that therapeutically can be used as a BRONCHODIIATOR in ANTIASTHMATIC treatment, hexoprenaline hydrochloride hexoprenaline. hexuronic acid ascorbic acid, hexylcaine [inn] (hexylcaine hydrochloride [usan]) is an ester series LOCAL ANAESTHETIC, used by topical application for the local relief of pain, hexylcaine hydrochloride hexylcaine. hexylresorcinol [usan] is a urinary ANTISEPTIC and an ANTHELMINTIC. It inhibits melanosis (blackspot) in shrimps, and is used as a food additive for prevention of enzymic browning in shrimps and fruits, hexyltheobromine pentifylline. 

Note The prolonged use of chlorpromazine can produce a gray-blue or purplish pigmentation over light-exposed areas. This is a result of either dermal deposits of melanin, a chlorpromazine metabolite, or to a combination of both. Chlorpromazine melanosis is seen more often in women... 

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