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dermatoheliosis (photoaging, skin aging)

Polymorphic response of epidermal cells, dermal connective tissue & vascular system to prolonged &/or excessive exposure to ultraviolet radiation. Etiology: 1) ultraviolet B (290-320 nm) is most potent offender 2) ultraviolet A (320-400 nm) can induce the same pathology Epidemiology: 1) whites 2) most often in individuals > 40 years of age 3) higher incidence in males 4) people living in high altitudes & low latitudes 5) individuals with outside occupation 6) individuals with inability to tan Pathology: 1) dermatopathology general a) severity depends upon the duration & intensity of sun exposure & facultative melanin pigmentation beginning with 1st exposures early in life b) increased fragility of skin c) decreased elasticity of skin 2) epidermis a) acanthosis of the epidermis b) increased horny layer c) flattening of the dermal-epidermal junction d) atypia of keratinocytes 3) dermis a) loss of small vessels in the papillary dermis b) elastosis c) an increase in fibroblasts d) decrease in collagen - decreased synthesis (specifically procollagen 1) - increased collagenase activity e) increase in elastin 4) molecular - cyclo-oxygenase 2 (COX2) may play a role [7] - COX2 is elevated in aged skin & photoaged skin - COX2 is higher in photoaged skin than normal aged skin - COX2 correlates with the degree of solar elastosis in photoaging [7] Genetics: - variations in MC1R influence severity of photoaging [2] - SNP in STXBP5L gene & haplotype linkage with another SNP that increases expression of FBXO40 is associated with less photoaging of facial skin [4] Clinical manifestations: 1) patient appears wrinkled, looks older than chronologic age a) coarse furrows b) fine wrinkles 2) irregular diffuse pigmentation 'bronzing' 3) actinic keratosis 4) solar lentigo & ephelides (development of freckles) [10] 5) telangiectasias, solar purpura, easy bruising 6) venous lakes 7) yellow dermal papules & plaques 8) loss of skin elasticity - pebbly texture of skin (elastosis) 9) comedones (especially periorbital) 10) distribution: sun-exposed areas Complications: - skin cancer - actinic purpura Differential diagnosis: - rosacea [9] - centrofacial location of redness, flushing, sensory change, & involvement of the nose suggest rosacea [9] - no finding definitively distinguishes the two [9] Management: 1) dermatoheliosis is generally progressive & irreversible a) may continue even after sun-exposure is restricted b) spontaneous reversal has been observed 2) Pharmacologic agents a) topical tretinoin b) topical 5-fluorouracil may cause disappearance of actinic keratosis c) methyl aminolevulinate (MAL) plus red light [2] - MAL is incubated for 3 hours under occlusion before an 8-minute red-light irradiation - treatments 3 weeks apart - associated with considerable pain - strictly avoid bright light for 1 or 2 days 3) prevention a) sunscreen - daily use of sunscreen can slow skin aging associated with middle age [5] b) protective clothing

Specific

Cutis rhomboidalis nuchae

General

skin disease (dermatologic disorder, dermatopathy, dermatosis)

References

  1. Color Atlas & Synopsis of Clinical Dermatology, Common & Serious Diseases, 3rd ed, Fitzpatrick et al, McGraw Hill, NY, 1997, pg 232-35
  2. Elfakir A et al. Functional MC1R-gene variants are associated with increased risk for severe photoaging in facial skin. J Invest Dermatol 2010 Apr; 130:1107. PMID: 19924138
  3. Sanclemente G et al. A prospective split-face double-blind randomized placebo- controlled trial to assess the efficacy of methyl aminolevulinate + red-light in patients with facial photodamage. J Eur Acad Dermatol Venereol 2011 Jan; 25:49 PMID: 20456545
  4. Le Clerc S et al. A genome-wide association study in Caucasian women points out a putative role of the STXBP5L gene in facial photoaging. J Invest Dermatol 2013 Apr; 133:929. PMID: 23223146
  5. Hughes MCB et al Sunscreen and Prevention of Skin Aging: A Randomized Trial. Ann Intern Med. 2013;158(11):781-790 PMID: 23732711 http://annals.org/article.aspx?articleid=1691733
  6. Medical Knowledge Self Assessment Program (MKSAP) 16, 17. American College of Physicians, Philadelphia 2012, 2015.
  7. Habib MA et al. Comparative immunohistochemical assessment of cutaneous cyclooxygenase-2 enzyme expression in chronological aging and photoaging. Photodermatol Photoimmunol Photomed 2014 Feb; 30:43 PMID: 24393208
  8. Geriatric Review Syllabus, 8th edition (GRS8) Durso SC and Sullivan GN (eds) American Geriatrics Society, 2013
  9. Helfrich YR et al. Clinical, histologic, and molecular analysis of differences between erythematotelangiectatic rosacea and telangiectatic photoaging. JAMA Dermatol 2015 Mar 23; [e-pub]. PMID: 25798811 - Wilkin JK. Erythematotelangiectatic rosacea and telangiectatic photoaging: Same, separate, and/or sequential? JAMA Dermatol 2015 Mar 23 PMID: 25798736
  10. Praetorius C, Sturm RA, Steingrimsson E Sun-induced freckling: ephelides and solar lentigines Pigment Cell Melanoma Res. 2014 May;27(3):339-50 PMID: 24517859 Review.
  11. Sunlight, Ultraviolet Radiation, and the Skin http://consensus.nih.gov/cons/074/074_intro.htm