Skin Pigmentation Disorders

Skin Pigmentation Disorders

Classify Pathological Pigmentation and Endogenous Pigments In Detail.
Answer:

Pigments are colored substances present in most living beings, including humans.

There are two broad categories of pigments:

• Endogenous
• Exogenous.

Skin pigmentation disorders

“Importance of early diagnosis of skin pigmentation issues”

Pathological Pigments

“Understanding skin pigmentation disorders: Types and symptoms”

Endogenous Pigments

Endogenous pigments are either normal constituents of cells or accumulate under special circumstances.

Melanin: It is a black, non-hemoglobin-derived pigment.

Hyperpigmentation

• It is normally present in hair, skin, choroid of the eye, meninges, and adrenal medulla.
• It is synthesized in melanocyte and dendritic cells.
• It is stored in the form of cytoplasmic granules in the phagocytic cells called melanophores.
• Hyperpigmentation occur during:
  • Addison’s disease
  • Chronic arsenic poisoning
  • Melanosis Coli
  • Melanotic tumor
• Hypopigmentation occurs during:
  • Albinism
  • Leucoderma.
  • Vitiligo
  • Leprosy
  • Radiation dermatitis.

“Common types of skin pigmentation disorders explained”

Staining characteristics of melanin: It can be bleached by hydrogen peroxide and is stained with Masson-Fontana argentaff stain, this differentiates the melanin from melanin look-alikes.

Ochronosis: The pigment is melanin-like and is deposited both intracellularly and intercellularly.

• The most commonly affected tissues are cartilage, capsules of joints, ligaments, and tendons.

Skin discoloration causes

“Global prevalence of skin pigmentation disorders”

Hemoprotein Derived Pigment:

• Hemosiderin: It is formed by the aggregation of ferritin.
  • It is golden yellow to the brown crystalline, granular pigment that stains with Prussian blue stain.
  • It is found within mononuclear phagocytes of bone, spleen, and liver, where the breakdown of RBC occurs.
  • Severe progressive iron overload leading to fibrosis and organ failure is known as hemochromatosis.
• Acid hematin (Hemozoin): It is a hemoprotein-derived brown-black pigment.
  • It contains heam iron in the ferric form in an acidic medium.
  • It is seen most commonly in chronic malaria and mismatched blood transfusions.
• Bilirubin: It is an iron-containing pigment present in bile and stain with a gmelin reaction.
  • It is derived from the porphyrin ring of hemoglobin.
  • Excess bilirubin causes jaundice.
• Porphyrins: They are tetrapyrrole in heam. It contains iron.
  • Porphyria results from the genetic deficiency of one of the enzymes required for the synthesis of heam.

“Impact of UV exposure on skin pigmentation changes”

Lipofuscin: It is also known as wear and tear pigment.

• Lipofuscin or lipochrome is a yellowish-brown granular intracytoplasmic lipid pigment.
• The pigment is found in atrophied cells of old age.
• It is seen in myocardial fibers, hepatocytes, Leydig cells of the testis, and neurons in senile dementia.
• In heart muscle change is associated with wasting of muscle and is commonly referred to as brown atrophy.

“Treatment options for common skin pigmentation disorders”

Staining characteristics of lipofuscin

• It is acid-fast
• Autofloroscent
• Stain positive with fat stains
• Reduces ferricyanide to ferrocyanide.