Disorders of skin color   DR. Ali El-ethawi   Specialist  Dermatologist  M.B.CH.B ,  F.I.C.M.S,  C.A.B.D 5 th  class lectu...
Normal skin color <ul><li>is composed of a mixture of four biochromes ,  </li></ul><ul><li>melanin (brown).  </li></ul><ul...
Differences in racial pigmentation <ul><li>Not due to differences in melanocyte number but from differences in melanocyte ...
The epidermal melanin unit
Normal skin color <ul><li>Constitutive  skin color ;  There  are three basic skin colors( black, white and brown ) which a...
Disorders of skin color <ul><li>These disorders are  Congenital or acquired ,  Diffuse or circumscribed ,  </li></ul><ul><...
Some causes of hypopigmentation  <ul><li>Congenital: </li></ul><ul><li>1. Circumscribed : e.g; </li></ul><ul><li>* Piebald...
 
<ul><li>Hypopigmenation : almost invariably related to decrease production of melanin,  </li></ul><ul><li>e.g. pityriasis ...
Vitiligo <ul><li>The word  vitiligo   may be derived from the Greek  vitelius ,  signifying a &quot;calf's white patches ....
Vitiligo <ul><li>Clinically:   Milky-white macules of different sizes & shapes gradually spread peripherally. </li></ul><u...
 
Vitiligo <ul><li>Inheritance ; </li></ul><ul><li>Vitiligo has a genetic background ;  </li></ul><ul><li>>  30%  had +ve  F...
 
 
 
Types  <ul><li>Focal vitiligo  ; </li></ul><ul><li>Usually a solitary macule or a few scattered macules in one area,  </li...
 
 
 
Differential Diagnosis <ul><ul><li>Pityriasis alba  (slight scaling, fuzzy margins, off-white color).  </li></ul></ul><ul>...
Course and Prognosis <ul><li>Vitiligo is a  chronic  disease.  </li></ul><ul><li>The course is highly  variable , but  rap...
R x of vitiligo  <ul><li>Sunscreens;   Sunscreens help prevent sunburn and thus may lessen photodamage as well as the chan...
Albinism <ul><li>A group of genetic disorder in which there is little or no melanin pigment in skin, hair follicles, and e...
 
Pityriasis alba <ul><li>It is a common finding (5% of children) that is probably more usual in patients with the atopic di...
<ul><li>Pityriasis versicolor . A. Typical macules are round, very well circumscribed, have  fine scale , and are  off-whi...
Tuberous sclerosis. Ash leaf-shaped hypopigmented  macules.
Some causes of Hyperpigmentation <ul><li>Genetic  </li></ul><ul><li>Freckles </li></ul><ul><li>Lentigo </li></ul><ul><li>P...
Melasma <ul><li>   </li></ul><ul><li>Melasma (Greek: &quot;a black spot&quot;) , Synonyms : Chloasma (Greek: &quot;a green...
 
R x of melasma  <ul><li>Treatment is aimed at reducing the increased pigmentation that develops in melasma  . </li></ul><u...
Freckles <ul><li>Freckles or ephelides   ; </li></ul><ul><li>small, red or light- brown macules </li></ul><ul><li>most oft...
Freckles
Lentigo <ul><li>They are benign discrete hyperpigmented macules  </li></ul><ul><li>The intensity of the color  is not  dep...
Peutz-Jeghers syndrome (PJS) <ul><li>is  characterized by hyperpigmented macules on the  lips  and  oral mucosa  and  poly...
Erythema ab igne <ul><li>brown hyperpigmentation with a  reticular pattern  develops with   Chronic  repeated exposure, th...
Cafe-au-lait (CAL)spots <ul><li>CAL spots are uniformly  pale brown macules  that vary in size from  0.5 to 20 cm  can be ...
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dermatology.Disorders of skin color.(dr.ali)

  1. 1. Disorders of skin color DR. Ali El-ethawi Specialist Dermatologist M.B.CH.B , F.I.C.M.S, C.A.B.D 5 th class lecture
  2. 2. Normal skin color <ul><li>is composed of a mixture of four biochromes , </li></ul><ul><li>melanin (brown). </li></ul><ul><li>reduced hemoglobin ( blue ), </li></ul><ul><li>(3) Oxy hemoglobin (red ), </li></ul><ul><li>(4) carotenoids (yellow ; exogenous from diet ) </li></ul><ul><li>The major skin color determinants: is Melanin which is formed from </li></ul><ul><li>tyrosine, via the action of tyrosinase, in the melanosomes of epidermal melanocytes. </li></ul><ul><li>So the visible pigmentation of the skin or hair is a combination of the </li></ul><ul><li>amount of melanin, type of melanin (eumelanin versus pheomelanin),degree of vascularity, and presence of carotene. Other materials can be deposited abnormally in the skin leading to pigmentation. </li></ul>
  3. 3. Differences in racial pigmentation <ul><li>Not due to differences in melanocyte number but from differences in melanocyte activity. </li></ul>
  4. 4. The epidermal melanin unit
  5. 5. Normal skin color <ul><li>Constitutive skin color ; There are three basic skin colors( black, white and brown ) which are determined genetically. </li></ul><ul><li>Inducible skin color ; the normal basic skin color pigmentation can be increased by exposure to UVR or pituitary hormones. </li></ul><ul><li>skin phototype (SPT ) . </li></ul><ul><li>This is a combination of the constitutive and inducible skin color. ( SPT 1- 6) </li></ul><ul><li>The skin phototype is a marker for skin cancer risk and should be recorded at the first patient visit </li></ul><ul><li>Ethnicity is not necessarily a part of the definition, </li></ul><ul><li>e.g., African &quot; black &quot; ethnic persons can be SPT- III </li></ul><ul><li>and an East Indian Caucasian can be SPT IV or even V. </li></ul>
  6. 6. Disorders of skin color <ul><li>These disorders are Congenital or acquired , Diffuse or circumscribed , </li></ul><ul><li>Isolated or part of a syndrome , Epidermal or dermal , With or without inflammation . </li></ul><ul><li>Altered skin pigmentation may be caused by </li></ul><ul><li>Increased or decreased melanin, </li></ul><ul><li>Abnormal melanin distribution, </li></ul><ul><li>Decreased hemoglobin, </li></ul><ul><li>Deposition of exogenous pigments </li></ul>
  7. 7. Some causes of hypopigmentation <ul><li>Congenital: </li></ul><ul><li>1. Circumscribed : e.g; </li></ul><ul><li>* Piebaldism </li></ul><ul><li>* Nevus depigmentaosus </li></ul><ul><li>2. Generalized : </li></ul><ul><li>* Albinism </li></ul><ul><li>* Phenylketonuria </li></ul><ul><li>* Homocytineuria </li></ul><ul><li>Nutritional </li></ul><ul><li>* Kwashiokor </li></ul><ul><li>* Selenium deficiency </li></ul>Endocrine : * Hypopituitarism * Thyroid disease Secondary to physical trauma : * Burns * Trauma * Post-dermabrasion * Post-laser Secondary to chemical exposure : ( occupational or therapeutic ) Monobenzyl ether of hydroquinone; phenol ( certain ); steroids; Azelaic acid; Retionoids.
  8. 9. <ul><li>Hypopigmenation : almost invariably related to decrease production of melanin, </li></ul><ul><li>e.g. pityriasis alba, seborrheic dermatitis, albinism, tinea versicolor, nevus depigmentosus, congenital syndromes </li></ul><ul><li>Depigmenation : almost invariably related to absence of melanocytes </li></ul><ul><li>e.g. vitiligo, piebaldism, scarring (DLE) </li></ul>
  9. 10. Vitiligo <ul><li>The word vitiligo may be derived from the Greek vitelius , signifying a &quot;calf's white patches .“ </li></ul><ul><li>A chronic disorder with multifactorial, genetic predisposition and triggering factors such as trauma, sunburn, stress, and systemic illness. </li></ul><ul><li>EPIDEMIOLOGY; </li></ul><ul><li>Incidence; Common, worldwide with a prevalence of 1 % to 2 % </li></ul><ul><li>Sex; Equal in both sexes. </li></ul><ul><li>Age of Onset ; May begin at any age, but in 50% of the patients develop vitiligo before the age of 20, & the incidence decreases with increasing age. </li></ul><ul><li>Race ; All races. </li></ul>
  10. 11. Vitiligo <ul><li>Clinically: Milky-white macules of different sizes & shapes gradually spread peripherally. </li></ul><ul><li>Sites ; Most common sites are periorificial, face, genitals, mucous membranes, extensor surfaces, hands, and feet . </li></ul><ul><li>Microscopically vitiligo is characterized by complete absence of melanocytes . </li></ul><ul><li>Association ; systemic autoimmune and/or endocrine diseases, and, rarely, malignant melanoma. </li></ul><ul><li>40% of patients have ocular pigmentary abnormalities </li></ul><ul><li>Wood's light Examination the examination is done in a dark room, accentuates the hypopigmented areas and useful is for examining patients with light complexions. </li></ul>
  11. 13. Vitiligo <ul><li>Inheritance ; </li></ul><ul><li>Vitiligo has a genetic background ; </li></ul><ul><li>> 30% had +ve FH. </li></ul><ul><li>Transmission is most likely polygenic with variable expression. </li></ul><ul><li>Pathogenesis </li></ul><ul><ul><li>The autoimmune theory ,melanocytes are destroyed by certain lymphocytes that have somehow been activated. </li></ul></ul><ul><ul><li>The neurogenic hypothesis ,is based on an interaction of the melanocytes and nerve cells. </li></ul></ul><ul><ul><li>The self-destruct hypothesis ,melanocytes are destroyed by toxic substances formed as part of normal melanin biosynthesis </li></ul></ul>
  12. 17. Types <ul><li>Focal vitiligo ; </li></ul><ul><li>Usually a solitary macule or a few scattered macules in one area, </li></ul><ul><li>Segmental vitiligo </li></ul><ul><li>: Unilateral macules in a dermatomal or quasi-dermatomal distribution. </li></ul><ul><li>Acrofacial vitiligo : </li></ul><ul><li>Depigmentation of the distal fingers and periorificial areas. </li></ul><ul><li>Generalized vitiligo : (vitiligo vulgaris), </li></ul><ul><li>the most common pattern. Depigmented patches are widely and usually symmetrically distributed. </li></ul><ul><li>Universal vitiligo ; </li></ul><ul><li>Depigmented macules and patches over most of the body, often associated with multiple endocrinopathy syndrome. </li></ul><ul><li>Mucosal vitiligo : </li></ul><ul><li>Involvement of the mucus membrane. </li></ul>
  13. 21. Differential Diagnosis <ul><ul><li>Pityriasis alba (slight scaling, fuzzy margins, off-white color). </li></ul></ul><ul><ul><li>Pityriasis versicolor (fine scales with greenish-yellow fluorescence under Wood's lamp, positive KOH. </li></ul></ul><ul><ul><li>Leprosy (endemic areas, off-white color, usually ill-defined anesthetic macules). </li></ul></ul><ul><ul><li>Nevus depigmentosus (stable, congenital, off-white macules, unilateral). </li></ul></ul><ul><ul><li>Nevus anemicus (does not enhance with Wood's lamp; does not show erythema after rubbing). </li></ul></ul><ul><ul><li>Tuberous sclerosis  : stable, congenital off-white macules ( ash-leaf shape) . </li></ul></ul><ul><ul><li>Piebaldism (congenital, white forelock, stable, dorsal pigmented stripe on back, distinctive pattern with large hyperpigmented macules in the center of the hypomelanotic areas). </li></ul></ul><ul><ul><li>Postinflammatory leukoderma  [off-white macules (usually a history of psoriasis or eczema in the same macular area), not so sharply defined]. </li></ul></ul><ul><ul><li>Mycosis fungoides (may be confusing as only depigmentation may be present and biopsy is necessary). </li></ul></ul>
  14. 22. Course and Prognosis <ul><li>Vitiligo is a chronic disease. </li></ul><ul><li>The course is highly variable , but rapid onset followed by a period of stability or slow progression is most characteristic . </li></ul><ul><li>some spontaneous repigmentation Up to 30% of patients </li></ul><ul><li>Rapidly progressive vitiligo may quickly lead to extensive depigmentation with a total loss of pigment in skin and hair, but not eyes . </li></ul>
  15. 23. R x of vitiligo <ul><li>Sunscreens; Sunscreens help prevent sunburn and thus may lessen photodamage as well as the chance that a Koebner phenomenon will occur </li></ul><ul><li>Cosmetics ; Many patients, especially patients with focal vitiligo , find cosmetic cover-ups to be a valuable treatment option. </li></ul><ul><li>Topical Corticosteroids ; for limited areas of vitiligo and are often the first line of therapy for children </li></ul><ul><li>Topical Immunomodulators; Topical tacrolimus ointment is effective localized vitiligo particularly on the face and neck. </li></ul><ul><li>Topical Calcipotriol ; produces cosmetically acceptable repigmentation in some patients with vitiligo. </li></ul><ul><li>Pseudocatalase ; Catalase , an enzyme normally found in skin that decreases damage from free radicals, has been reported to be low in the skin of vitiligo patients. </li></ul><ul><li>------------------------------------------------------------------------------------------------------------------------------------------------------- </li></ul><ul><li>Systemic Therapies ; systemic corticosteroids have been used as pulse therapy with variable results and may prevent rapid depigmentation in active disease </li></ul><ul><li>Psoralen and Ultraviolet A Therapy (PUVA ) Topical or oral 8-methoxypsoralen combined with UVA (320 to 400 nm) irradiation (PUVA) is effective for treating vitiligo, </li></ul><ul><li>Narrowband Ultraviolet B Radiation (NB –UVB-311 nm ) is considered by many to be the first choice for most patients. </li></ul><ul><li>Excimer Laser (308 nm) ; has been recently studied in several trials for its efficacy in treating vitiligo </li></ul><ul><li>Depigmentation ; Monobenzyl ether of hydroquinone (Monobenzone 20% cream ) for depigmenting residual normal skin in patients with extensive vitiligo,it is a permanent, irreversible process </li></ul><ul><li>Mini-skingrafting may be a useful technique for refractory and stable segmental vitiligo macules </li></ul>
  16. 24. Albinism <ul><li>A group of genetic disorder in which there is little or no melanin pigment in skin, hair follicles, and eyes. </li></ul><ul><li>Normal number of melanocytes are present but with reduced or absent tyrosinase positivity so, there is defect in the synthesis of melanin (tyrosinase +ve or –ve) </li></ul><ul><li>Albinism of the eyes and skin : occulocutaneous albinism (OCA); </li></ul><ul><li>Albinism can affect the eyes: ocular albinism (OA); </li></ul><ul><li>The cutaneous phenotype of the various forms of albinism is </li></ul><ul><li>broad, but the ocular phenotype is reasonably </li></ul><ul><li>constant in most forms. </li></ul><ul><li>World-wide occurrence. </li></ul><ul><li>Albinism is usually a recessive trait. </li></ul><ul><li>Clinical features ; the whole skin is white &pigment </li></ul><ul><li>is also lacking In the hair ,iris &retina </li></ul><ul><li>The albinos have poor sight , photophobia </li></ul><ul><li>&rotary Ocular nystagmus </li></ul><ul><li>Complication; development of sun- induced skin tumors </li></ul><ul><li>even when they are young . </li></ul>
  17. 26. Pityriasis alba <ul><li>It is a common finding (5% of children) that is probably more usual in patients with the atopic diathesis. </li></ul><ul><li>Age ; The condition appears in most instances before puberty. </li></ul><ul><li>Site ;The most common sites are the face, neck, and arms. </li></ul><ul><li>C/F; The lesions begin as a non-specific erythema and gradually </li></ul><ul><li>become scaly and hypopigmented. </li></ul><ul><li>Cause ;The hypopigmentation is transient </li></ul><ul><li>and caused by mild dermal inflammation. </li></ul><ul><li>The condition gradually improves after puberty. </li></ul><ul><li>D.DX ; vitiligo and tinea versicolor . </li></ul><ul><li>Treatment </li></ul><ul><li>consists of lubrication. </li></ul><ul><li>Mild inflammation responds to mild topical steroids </li></ul>
  18. 27. <ul><li>Pityriasis versicolor . A. Typical macules are round, very well circumscribed, have fine scale , and are off-white to tan colored.. </li></ul><ul><li>B. Confluent macules create scalloped borders. This is a characteristic pattern of macules of pityriasis versicolor. </li></ul>
  19. 28. Tuberous sclerosis. Ash leaf-shaped hypopigmented macules.
  20. 29. Some causes of Hyperpigmentation <ul><li>Genetic </li></ul><ul><li>Freckles </li></ul><ul><li>Lentigo </li></ul><ul><li>Peutz Jeghers syndrome </li></ul><ul><li>Café au lait spots </li></ul><ul><li>Xeroderma pigmentosa </li></ul><ul><li>Endocrine </li></ul><ul><li>Addison's disease </li></ul><ul><li>Cushing’s syndrome </li></ul><ul><li>Pregnancy </li></ul><ul><li>Renal failure </li></ul><ul><li>Metabolic </li></ul><ul><li>Biliary cirrhosis </li></ul><ul><li>Hemochromatosis </li></ul><ul><li>Porphyria </li></ul><ul><li>Nutritional </li></ul><ul><li>Mal absorption </li></ul><ul><li>Pellagra </li></ul><ul><li>Drugs </li></ul><ul><li>Photosensetizing </li></ul><ul><li>minocycline </li></ul><ul><li>arsenic </li></ul><ul><li>psoralens </li></ul><ul><li>busulfan </li></ul><ul><li>estrogens &progesterone </li></ul><ul><li>Postinflammatory </li></ul><ul><li>lichen planus </li></ul><ul><li>Eczema </li></ul><ul><li>Secondary syphilis </li></ul><ul><li>Systemic sclerosis </li></ul><ul><li>Macular &Lichen amyloidosis </li></ul><ul><li>Cryotherapy </li></ul><ul><li>Tumors </li></ul><ul><li>Malignant melanoma </li></ul><ul><li>Pigmented nevi </li></ul><ul><li>Acanthosis nigricans </li></ul><ul><li>Mastocytosis </li></ul><ul><li>other </li></ul><ul><li>Melasma </li></ul><ul><li>Erythema ab igne </li></ul>
  21. 30. Melasma <ul><li>  </li></ul><ul><li>Melasma (Greek: &quot;a black spot&quot;) , Synonyms : Chloasma (Greek: &quot;a green spot&quot;), mask of pregnancy </li></ul><ul><li>It is an acquired light- or dark-brown hyperpigmentation that occurs in the exposed areas, most often on the face, and results from exposure to sunlight. </li></ul><ul><li>Etiology . Genetic factors and UV radiation are the most important causes. </li></ul><ul><li>Other causes include ; </li></ul><ul><li>pregnancy, oral contraceptives, estrogen-progesterone therapies, </li></ul><ul><li>thyroid dysfunction, cosmetics phototoxic and anti -seizure drugs. </li></ul><ul><li>Age of Onset ; Young adults. </li></ul><ul><li>Sex; Females > males; about 10% of patients with melasma are men. </li></ul><ul><li>Race ; Melasma is more apparent or more frequent in persons with brown or black constitutive skin color (persons from Asia, the Middle East, India, South America). </li></ul><ul><li>Melasma may not resolve after delivery or withdrawal of oral contraceptives. </li></ul><ul><li>Mild subclinical ovarian dysfunction may be present in some patients . </li></ul><ul><li>There are three clinical patterns : centrofacial, malar, and mandibular </li></ul><ul><li>There are three types based on Wood's light examination : </li></ul><ul><li>1.epidermal type. The pigmentation is intensified by Wood's light examination </li></ul><ul><li>2 . dermal type ; The pigmentation does not show enhancement with the Wood's light </li></ul><ul><li>3.mixed type </li></ul>
  22. 32. R x of melasma <ul><li>Treatment is aimed at reducing the increased pigmentation that develops in melasma . </li></ul><ul><li>Sun protection ; </li></ul><ul><li>It is essential that the patient use, every morning, an opaque sunblock containing titanium dioxide and/or zinc oxide; </li></ul><ul><li>Topical depigmented agents </li></ul><ul><li>hydroquinone 2% , 4% cream; </li></ul><ul><li>combination of flucinolone , hydroquinone , and tretinoin . </li></ul><ul><li>azelaic acid 20% cream; </li></ul><ul><li>Kojic acid, retinoids </li></ul><ul><li>Others ; chemical peels , laser therapy , and dermabrasion. </li></ul>
  23. 33. Freckles <ul><li>Freckles or ephelides ; </li></ul><ul><li>small, red or light- brown macules </li></ul><ul><li>most often found in individuals with fair complexions </li></ul><ul><li>are promoted by sun exposure and fade during the winter months. </li></ul><ul><li>They are usually confined to the face, arms, and back. </li></ul><ul><li>from a few spots on the face to hundreds of confluent macules on the face and arms. </li></ul><ul><li>They usually appear around age 5 year </li></ul><ul><li>may be genetically determined (as AD trait) and may recur in successive generations in similar locations and patterns </li></ul><ul><li>Freckle must be differentiated from lentigo simplex </li></ul><ul><li>No treatment is necessary </li></ul><ul><li>appropriate sun protection is need </li></ul>
  24. 34. Freckles
  25. 35. Lentigo <ul><li>They are benign discrete hyperpigmented macules </li></ul><ul><li>The intensity of the color is not dependent on sun exposure. </li></ul><ul><li>Appearing at any age and on any part of the body , including the mucosa. </li></ul><ul><li>The backs of the hands and face (especially the forehead) are favored sites. </li></ul><ul><li>Simple lentigo arise most often in Childhood as a few scattered lesions ,most often on areas not exposed to sun, including mucous membrane . </li></ul><ul><li>solar lentigo (frequently misnamed &quot;liver spot&quot;) appears at a later age, mostly in persons with long-term sun exposure </li></ul><ul><li>Simple lentigo and senile lentigo looks alike </li></ul><ul><li>RX; lentigenes are best prevented by appropriate sun protection. </li></ul><ul><li>Cryotherapy, topical tretinoin, and adapalene are effective in the treatment of solar lentigenes. </li></ul><ul><li>Laser like Q-switched ruby 694 nm, Q-switched alexandrite 755nm … are extremely effective for treating ugly lesions. </li></ul>
  26. 36. Peutz-Jeghers syndrome (PJS) <ul><li>is characterized by hyperpigmented macules on the lips and oral mucosa and polyposis of the small intestine . </li></ul>
  27. 37. Erythema ab igne <ul><li>brown hyperpigmentation with a reticular pattern develops with Chronic repeated exposure, the eruption initially appears as bands of erythema </li></ul><ul><li>Cause ; Chronic exposure to heat from a wood stove, fireplace, electric blanket, electric heater, hot water bottle, or hot compress </li></ul>
  28. 38. Cafe-au-lait (CAL)spots <ul><li>CAL spots are uniformly pale brown macules that vary in size from 0.5 to 20 cm can be found on any cutaneous surface </li></ul><ul><li>They may be present at birth , are 10% to 20% of normal children , and increase in number and size with age. </li></ul><ul><li>in children over 5 years of age : Six or more spots > 1.5 cm in diameter are presumptive evidence of neurofibromatosis (von Reckling hausen's disease) . </li></ul><ul><li>In children under 5 years of age , five or more cafe-au-lait spots greater than 0.5 cm in diameter suggest the diagnosis of neurofibromatosis. </li></ul><ul><li>CAL spots are present in 90% to 100% of patients with von Recklinghausen's disease </li></ul>
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