Pigmentation abnormalities Flashcards
DDX for lentigo
1) pigmented nevi
2) pigmented viral plaques
3) pigmented tumors (melanocytic neoplasia in H)
What are causes of nevi
1) epidermal nevi
2) melanocytic nevi
3) comedo nevi
What are the reasons for acquired hyperpigmentation
- post-inflammatory
- comedone associated -demodicosis, HAC, pressure, trauma, comedo nevus
- hormone associated + uv, mitotane
- drug induced- mitotane, minocycline, cabergoline, ketokonazole
- papillomavirus
- pigmeneted tumors
- fungal (pheohypomycosis)
what are the causes of hypopigmenation
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
Causes of vitiligo
- Autoimmunity: antimelanocyte antibodies, antimelanocyte T cells; can co-exist with other autoimmune diseases like primary hypoadrenocorticism
- Autotoxicity: melanin precursors (dopachrome) or reduced radical scavengers (thioredoxine reductase)
- Neural: distribution to dermatomes
- Others: virus (cytomegalovirus); lack of growth factors, melatonin
what is the difference between snow nose and dudley nose
Dudley nose: present from birth
Snow nose: acquired and seasonal
What are the causes of post inflammatory hypopigmentation
- Bacterial: folliculitis (groin, inguinal area), mucocutaneous
- Mycoses: sporotrichosis, blastomycosis
- Leishmaniosis
- Contact dermatitis: nose, lips (plastic or rubber food dishes)
- Autoimmune: DLE, SLE, PE, PF, BP, drug eruption, uveodermatologic syndrome
Name causes of acquired hypopigmentation
- Post inflammatory
- drug related
- metabolic/hormonal
- neoplasia
- idiopathic
- periocular leukotrichia (siamese)
- rubber toxicity
What are metabolic/hormonal causes of hypopigmentation
- Hormonal: sex hormone dermatoses (males)
- Nutritional: Zn, pyridoxone, pantothenic acid, lysine, Cu; tyrosine or phenylalanine
- Spaying: hair coat depigmentation can accompany the changes in the hair coat texture
What are the causes of red hair
- Saliva, tears (porhyrins)
- Diet: poor protein quality, Cu deficiency, amino acid deficiency
- Hormonal: hypothyroidism, Cushing, Sertoli cell tumor, hyperestrogenism, hyperprogesteronism
- Environmental influences: UV light, chloride, detergents
What is the pathogenesis of flushing
vasodilation due to emotional, autonomic, endocrine causes or vasoactive compounds
-persistent or paroxyzmal
What are the causes of flusing
- Demodicosis (D): persistent
- SLE (D): persistent
- Drugs: persistent or paroxysmal
- Eosinophilic dermatitis with edema (Well’s-like syndrome): persistent
- Thallium toxicosis (D): persistent
- Mast cell tumor or systemic mastocytosis: persistent or paroxysmal
- Cutaneous lymphoma (D): persistent
- Pheochromocytoma (D): paroxysmal
- Carcinoid syndrome (D): paroxysmal
What are the differences between eyes of albino and Warndeburg Klein syndrome
- Albino- red eyes
-when looked they have slight bluish apperanace and the iris is actually transparent
-we see RBC in retina - blue- WK syndrome
-its the optical effect on non pigmented iris
