Mosaic subclinical melanoderma: an Achilles heel for UV-related epidermal carcinogenesis?

in International Journal of Oncology (2004), 25(6), 1763-7

Cutaneous cancers are not uncommon on the face of elderly patients. Melanin should protect, at least in part, against the ultraviolet (UV)-induced neoplastic damage. However, the density in melanin ... [plus ▼]

Cutaneous cancers are not uncommon on the face of elderly patients. Melanin should protect, at least in part, against the ultraviolet (UV)-induced neoplastic damage. However, the density in melanin chromatophores is heterogeneous in the epidermis of Caucasian adults. The computerized UV light-enhanced visualization (ULEV) method is a sensitive tool to assess non-invasively this mosaic pattern of intra-epidermal melanin load. In this study, the combination of ULEV pattern analysis and image analysis were performed involving four groups of phototype III Caucasian subjects. The first group was composed of 55 patients aged from 65 to 75 years who suffered from several malignancies of facial skin. The second control group of 55 patients who never had developed skin cancers were matched with the first group for age, sex and phototype. The third group was composed of 80 patients aged from 49 to 59 years who had developed a single basal cell carcinoma. The fourth group comprised 80 age, sex and phototype-matched healthy control subjects. Irrespective of the groups of subjects, a correlation was found between the pattern grading and the objectively determined relative area of subclinical melanoderma. Patients with multiple skin cancers differed from the other groups by the fact that a significantly higher proportion of them exhibited an extensive type of subclinical melanoderma. This feature was also seen in a minority of patients with a single basal cell carcinoma. The extensive subclinical melanoderma pattern is interpreted as a clue for risk, but not as a cause of UV-induced skin carcinogenesis. [moins ▲]

Ultraviolet light-enhanced visualization of cutaneous signs of carotene and vitamin A dietary deficiency.

in Acta Clinica Belgica (2004), 59(2), 97-101

Dietary deficiencies are multiple and some of them may induce specific changes in the skin biology and structure. Vitamin A deficiency is well identified as a cause of xerosis and follicular keratosis ... [plus ▼]

Dietary deficiencies are multiple and some of them may induce specific changes in the skin biology and structure. Vitamin A deficiency is well identified as a cause of xerosis and follicular keratosis. Skin of the forehead and balding scalp was examined in 3 homeless alcoholic men who suffered from altered liver functions and denutrition including carotene and vitamin A deficiencies. The ultraviolet light-enhanced visualization (ULEV) method was used with a computer-assisted video camera equipped with an internal ultraviolet-emitting unit. Twenty healthy age- and phototype-matched men served as controls. Subclinical alterations of the stratum corneum and tiny follicular horny spikes at the skin surface were disclosed by ULEV. They were consistent with discrete flakiness on the forearms. By contrast, skin of the face and scalp showed follicular horny impactions corresponding to kerosis without any evidence for interfollicular xerosis. The skin condition was markedly improved after a 10-week dietary normalization. It is concluded that the ULEV method reveals some of the mildest and subclinical skin changes secondary to carotene and vitamin A deficiency. It could tentatively be used as a cheap and non-invasive aid in clinical screening programs among populations at risk. [moins ▲]

Skin-lightening products revisited.

in International Journal of Cosmetic Science (2003), 25(4), 169-81

Skin colour typology depends on the amount and location of its chromophores. Among them, eumelanins derived from 5,6-dihydroxyindole-2-carboxylic acid (DHICA) and 5,6-dihydroxyindole (DHI), and ... [plus ▼]

Skin colour typology depends on the amount and location of its chromophores. Among them, eumelanins derived from 5,6-dihydroxyindole-2-carboxylic acid (DHICA) and 5,6-dihydroxyindole (DHI), and phaeomelanins are of utmost importance. These biomolecules result from the multi-step enzymatic and non-enzymatic conversion of tyrosine into melanins. Pigmentation disorders are multiple and depend on alterations in the density in active melanocytes, and on specific abnormalities of any of the complex melanogenesis mechanisms. This review presents some of the main skin-lightening agents with respect to their mechanisms of action and side-effects. Some of the novel compounds may lead to new perspectives in the fields of dermatology and cosmetology. The methods commonly used to assess efficacy of skin-lightening products rely on in vitro models including cell-free enzymatic assays, melanocyte cultures and reconstructed epidermis bioassays. Animal models have little relevance. By contrast, human testing with the support of instrumental evaluations is the most informative. [moins ▲]

Regional variability in mottled subclinical melanoderma in the elderly.

in Experimental Gerontology (2003), 38(3), 327-31

The density in melanin chromatophores becomes heterogeneous in the epidermis during the early events of photoaging. Little is known about the regional variability in the resulting mottled skin appearance ... [plus ▼]

The density in melanin chromatophores becomes heterogeneous in the epidermis during the early events of photoaging. Little is known about the regional variability in the resulting mottled skin appearance on the sun-exposed parts of the body in the elderly. The relationship between these features and the dermal atrophy related to aging is also an area ripe for study. The aim of the present study was to objectively assess and compare such aspects of photoaging in older subjects. A computer-assisted video camera equipped with an internal ultraviolet-emitting unit (Visioscan) was used in combination with image analysis to quantify the infraclinical mottling of the skin on the forehead, neck and dorsal forearm. A Densi Score device served to assess the dermal atrophy by rating the skin folding capacity. A mottled subclinical melanoderma was disclosed on the three evaluation sites in all subjects irrespective of their phototypes. Three main patterns were identified corresponding to regular perifollicular dots, streaky macules along shallow wrinkles and unevenly shaped macules in the interfollicular area. The extent in melanoderma was larger on the forehead than on the neck and forearm. The age after 60 years did not influence the severity of mottled melanoderma, but clearly altered the skin folding capacity. The greatest inter-individual differences in mottled melanoderma were found in phototype II subjects. In conclusion, infraclinical mottled melanoderma is present in all individuals after 60 years of age. This type of epidermal photoaging does not appear to be influenced in older ages. By contrast, skin laxity due to dermal aging continues to progress beyond the age of 60 years. [moins ▲]

Assessment of topical hypopigmenting agents on solar lentigines of Asian women.

in Dermatology : International Journal for Clinical & Investigative Dermatology (2002), 204(4), 281-6

BACKGROUND: So-called darkened age spots encompass distinct pathological processes. The efficacy of topical depigmenting agents is difficult to objectivate. OBJECTIVE: To assess the hypopigmenting effect ... [plus ▼]

BACKGROUND: So-called darkened age spots encompass distinct pathological processes. The efficacy of topical depigmenting agents is difficult to objectivate. OBJECTIVE: To assess the hypopigmenting effect of three cosmetic formulations using objective biometrological methods. METHODS: 50 women of South-East Asian ancestry were enrolled in this pilot study. They had solar lentigines according to dermoscopic criteria. The lesions were treated by topical hypopigmenting formulations. Products were applied twice daily for 2 or 3 months. Assessments at 1-month intervals were made using narrow-band reflectance spectrophotometry, image analysis of video-recorded ultraviolet light reflection and photodensitometry- and image-analysis-assisted corneomelametry. RESULTS: A 20% azelaic acid formulation and another one containing 5% ascorbyl glucosamine, 1% kojic acid and alpha-hydroxyacid esters appeared inefficacious on solar lentigines. A stabilized soy extract showed a better although modest lightening effect when assessed by corneomelametry. The subclinical or faint mottled skin revealed by ultraviolet light examination better responded (p < 0.05) to treatments. CONCLUSION: Focal epidermal hyperpigmentation is better controlled by topical whitening agents when the increase in melanin content reflects a modest functional hyperactivity of melanocytes. [moins ▲]