PIGMENTARY DISORDER MIXED HYPO –HYPOMELANOSIS HYPERMELANOSIS AND HYPERMELANOSIS
Melanocytes• Populate the epidermis, hair follicle, eye, cochlea and meninges.• Synthesize melanin, and indole derivative of 3,4-dihydroxyphenylalanine that is stored in melanosomes.• Are influenced by endocrine, paracrine and aurocrine factors and by ultraviolet irradiation.
DEPIGMENTATION No inflammation WITH INFLAMMATIONVITILIGO & MELANOMA- ASSOCIATED LICHEN SCLEROSIS LEUKODERMA
…definition…An acquired absence of pigments found in spots or patches, although margin of these spots shows an increased amount of pigment matter.Vitiligo is multifactorial polygenic disorder with a complex pathogenesis.
The Roman physician Celsus firstused the term vitiligo in the second century AD. It is interesting to note that theRigveda (6000 BC or earlier) named leukoderma as kilas, meaning a white spotted deer.
etiology and pathogenesis• Unknown• Most preferable – endocrine disorders hypothesis.• Inhibited activity of enzyme in melanogenesis.• Allen – however, to start from or near an existing mole or from pressure.• Approximatly 20% of the pt with vitilgo have at least one first degree relative with vitiligo• Any age but mostly in children and adolescence
Disease mechanism…Vitiligo is associated with autoimmune and inflammatory diseases, found several mutations (single-nucleotide polymorphisms) in the NALP1 gene. The NALP1 gene, which is on chromosome 17 located at 17p13, is on a cascade that regulates inflammation and cell death, including myeloid and lymphoid cells, which are white cells that are part of the immune response. NALP1 is expressed at high levels in T cells and Langerhans cells, white cells that are involved in skin autoimmunity.
Disease mechanism…• Among the inflammatory products of NALP1 are caspase 1 and caspase 5, which activate the inflammatory cytokine interleukin-1β. Interleukin-1β is expressed at high levels in patients with vitiligo. There are compounds which inhibit caspase and interleukin- 1β, and so might be useful drugs for vitiligo and associated autoimmune diseases.• Of the 656 people, 219 had vitiligo only, 70 had vitiligo with autoimmune thyroid disease, and 60 had vitiligo and other autoimmune diseases. Addisons disease (typically an autoimmune destruction of the adrenal glands) may cause vitiligo.
Disease mechanism…• In one of the mutations, the amino acid leucine in the NALP1 protein was replaced by histidine (Leu155->His). The original protein and sequence is highly conserved in evolution, and found in humans, chimpanzee, rhesus monkey, and bush baby, which means that its an important protein and an alteration is likely to be harmful.• The following is the normal DNA and protein sequence in the NALP1 gene:• TCACTCCTCTACCAASerLeuLeuTyrGlnSLLYQIn• Some cases of vitiligo the first leucine is altered to histidine, by a Leu155→His mutation:• TCACACCTCTACCAASerHisLeuTyrGlnSHLYQ• (Leucine is nonpolar and hydrophobic; histidine is positively charged and hydrophilic, so it is unlikely both serve the same function)
Disease mechanism…• The normal sequence of the DNA code for NALP1 of TCACTCCTCTACCAA is replaced in some of these vitiligo families by the sequence TCACACCTCTACCAA,• which respectively code for the amino acid sequence of the normal NALP1 protein SLLYQ being replaced by SHLYQ.
location• Most common sites are periorificial, face, genitals, mucous mem., extensor surfaces, hands and feet• Onset – gradual, taking years to develop.• Found principally in tropics and in colored races.
sensation• No subjective sensation• But micro level mild inflammation of dermis and epidermis• Tendency for coalesce.• Koebnerization is common in vitiligo.• May associated with scleroderma, alopecia areata (Allen J H)
classification• Focal – solitary macule or few scattered , most commonly on distribution of trigeminal nerve, although the neck and trunk• Segmental vitiligo – unilateral macules, at early age, not with autoimmune disease, alteration of neural peptide has been implicated in the pathogenesis with patches of white hair…poliosis
• Acrofacial vitilgo – depigmentation of the distal fingers and periorificial areas.• Generalised vitiligo – also vitiligo vulgaris, the most common pattern, depigmented patches are widely and usually symmetrically distributed.• Universal vitiligo – depigmented macules and patches over most of the body, often associated with multiple endocrinopathy syndome.• Mucosal vitiligo – involvement of the mucus membrane sites only.
prognosis• Not favourable• Spontaneous recovery extremely rare…
treatment• In allied side, – Corticosteroids topical application – Furocoumarin agents like, Psoralen, Furalen, Beroxan etc along with lesion painted with as alcohol solution of meladine ( 1:1, 1:2)
…homoeopathy…J H ALLEN…No specificAlthough the tubercular diathesis appearing in many cases opens a field for investigations.DOUGLASS…our school but little better of.Locally, the pigmetation around the patch may prove servicable.Internally, sulphide of Arsenic, Nat Carb, Nit Acid, Sumbul and the Phosphide of Zinc may be studied.
• LILIENATHAL…• limited drugs with local applications.• So more overly the constitutional treatment is the best choice of remedy in case of vitiligo.• Sulphur, Ars Alb, Nit Acid, Nat Mur, Tub… various cases of these drugs in HOMOEOTIMES September 2005.
Differential Diagnosis• Idiopathic guttate hypomelanosis• Pityriasis versicolor• Pityriasis alba• Post inflammatory hypopigmentaion• Chemical leucoderma• Navus dipigmentosis• Piebaldism
• Differential Diagnosis – Pityriasis alba (slight scaling, fuzzy margins, off-white color). – Pityriasis versicolor alba (fine scales with greenish- yellow fluorescence under Woods lamp, positive KOH. – Chemical leukoderma (history of exposure to certain phenolic germicides, confetti macules). This is a difficult differential diagnosis, as melanocytes are absent as in vitiligo. – Leprosy (endemic areas, off-white color, usually ill- defined anesthetic macules). – Nevus depigmentosus (stable, congenital, off-white macules, unilateral). – Hypomelanosis of Ito (bilateral, Blaschkos lines, marble cake pattern; 60 to 75% have systemic involvement– CNS, eyes, musculoskeletal system). – Nevus anemicus (does not enhance with Woods lamp; does not show erythema after rubbing).
– Tuberous sclerosis [stable, congenital off-white macules (polygonal, ash-leaf shape, occasional segmental macules, and confetti macules)].– Piebaldism (congenital, white forelock, stable, dorsal pigmented stripe on back, distinctive pattern with large hyperpigmented macules in the center of the hypomelanotic areas).– Leukoderma associated with melanoma (may not be true vitiligo inasmuch as melanocytes, although reduced, are usually present).– Postinflammatory leukoderma [off-white macules (usually a history of psoriasis or eczema in the same macular area), not so sharply defined].– Mycosis fungoides (may be confusing as only depigmentation may be present and biopsy is necessary).– Vogt-Koyanagi-Harada syndrome (vision problems, photophobia, bilateral dysacousia).– Waardenburgs syndrome (commonest cause of congenital deafness, white macules and white forelock, iris heterochromia).
Vogt-koyanagi-harada syndrome• History of• Aseptic meningitis• Non traumatic uveitis,• Tinnitus• Hearing loss,• And/or dysacousis points for diagnosis of VKHS.• Its T cell mediated autoimmune disorders
• Piebaldism - dictionary meaning multi colored.• Type of congenital disorder of pigmentation.• Caused by mutation in the KIT proto- oncogene.• Generally depigmented patches on ventral or lateral trunk or mid- extremities.• Typically with deafness. back
Pityriasis alba• Benign condition mainly affecting head and neck region of preadolescent children.• Pink patch with elevated border progressed to non scaly hypoigmented macules persisting for months or years. back