Pigmentation abnormalities

Question 1

DDX for lentigo

Answer 1

1) pigmented nevi
2) pigmented viral plaques
3) pigmented tumors (melanocytic neoplasia in H)

Question 2

What are causes of nevi

Answer 2

1) epidermal nevi
2) melanocytic nevi
3) comedo nevi

Question 3

What are the reasons for acquired hyperpigmentation

Answer 3

1. post-inflammatory
2. comedone associated -demodicosis, HAC, pressure, trauma, comedo nevus
3. hormone associated + uv, mitotane
4. drug induced- mitotane, minocycline, cabergoline, ketokonazole
5. papillomavirus
6. pigmeneted tumors
7. fungal (pheohypomycosis)

Question 4

what are the causes of hypopigmenation

Answer 4

Hereditary:
1) melanocytopenic (absence of melanocytes)
2) melanopenic (decreased melanin)

Acquired:
1) destruction of melanocytes,
2) dysfunction of melanocytes,
3) abnormal dispersion of melanosomes (abnormal melanosome transfer, inflammation),
4) decreased melanosome production,
5) tyrosine defficiency

Question 5

Causes of vitiligo

Answer 5

1. Autoimmunity: antimelanocyte antibodies, antimelanocyte T cells; can co-exist with other autoimmune diseases like primary hypoadrenocorticism
2. Autotoxicity: melanin precursors (dopachrome) or reduced radical scavengers (thioredoxine reductase)
3. Neural: distribution to dermatomes
4. Others: virus (cytomegalovirus); lack of growth factors, melatonin

Question 6

what is the difference between snow nose and dudley nose

Answer 6

Dudley nose: present from birth
Snow nose: acquired and seasonal

Question 7

What are the causes of post inflammatory hypopigmentation

Answer 7

1. Bacterial: folliculitis (groin, inguinal area), mucocutaneous
2. Mycoses: sporotrichosis, blastomycosis
3. Leishmaniosis
4. Contact dermatitis: nose, lips (plastic or rubber food dishes)
5. Autoimmune: DLE, SLE, PE, PF, BP, drug eruption, uveodermatologic syndrome

Question 8

Name causes of acquired hypopigmentation

Answer 8

1. Post inflammatory
2. drug related
3. metabolic/hormonal
4. neoplasia
5. idiopathic
6. periocular leukotrichia (siamese)
7. rubber toxicity

Question 9

What are metabolic/hormonal causes of hypopigmentation

Answer 9

1. Hormonal: sex hormone dermatoses (males)
2. Nutritional: Zn, pyridoxone, pantothenic acid, lysine, Cu; tyrosine or phenylalanine
3. Spaying: hair coat depigmentation can accompany the changes in the hair coat texture

Question 10

What are the causes of red hair

Answer 10

1. Saliva, tears (porhyrins)
2. Diet: poor protein quality, Cu deficiency, amino acid deficiency
3. Hormonal: hypothyroidism, Cushing, Sertoli cell tumor, hyperestrogenism, hyperprogesteronism
4. Environmental influences: UV light, chloride, detergents

Question 11

What is the pathogenesis of flushing

Answer 11

vasodilation due to emotional, autonomic, endocrine causes or vasoactive compounds
-persistent or paroxyzmal

Question 12

What are the causes of flusing

Answer 12

1. Demodicosis (D): persistent
2. SLE (D): persistent
3. Drugs: persistent or paroxysmal
4. Eosinophilic dermatitis with edema (Well’s-like syndrome): persistent
5. Thallium toxicosis (D): persistent
6. Mast cell tumor or systemic mastocytosis: persistent or paroxysmal
7. Cutaneous lymphoma (D): persistent
8. Pheochromocytoma (D): paroxysmal
9. Carcinoid syndrome (D): paroxysmal

Question 13

What are the differences between eyes of albino and Warndeburg Klein syndrome

Answer 13

1. Albino- red eyes
   -when looked they have slight bluish apperanace and the iris is actually transparent
   -we see RBC in retina
2. blue- WK syndrome
   -its the optical effect on non pigmented iris