Dermatology Flashcards
(39 cards)
Factors influencing changes in skin colour
- Genetic
- Hormonal
- Inflammatory
- Autoimmune
Changes in skin colour may be considered as:
a. Congenital vs Acquired
b. Localized vs Generalized
Congenital causes of hypopigmentation include:
a. Albinism
b. Tuberous sclerosis
What is Albinism?
Autosomal recessive disorder of tyrosinase metabolism resulting in hypopigmentation
What are the different types of Albinism?
a. Ocular albinism: visual system affected (iris, retina)
b. Oculocutaneous albinism: skin, hair and eyes affected
What syndrome can Albinism be associated with?
Chediak Higashi syndrome
What features are seen in Chediak Higashi syndrome?
a. Hypopigmentation
b. Recurrent infections
c. Mild coagulation defects
d. Neurologic problems
What can be found on Physical Examination in a person with Albinism?
a. Hypopigmentation of skin, hair, eyes
b. Eyes: Nystagmus, strabismus, iris translucency, decr visual acuity, photophobia, amblyopia
c. Skin photosensitivity
What is the pathophys of Albinism
Disorder of tyrosinase metabolism–> partial or complete failure of melanin production from the melanocytes in the skin and/or the eyes–> hypopigmentation
What skin cancers can be seen with Albinism?
a. Actinic keratoses
b. Squamous cell carcinomas
c. Melanoma
Diagnosis of Albinism?
a. Skin Biopsy (test for melanin)
b. Genetic testing
How is Albinism managed?
a. Photoprotection (sunglasses, sunscreen)
b. Skin surveillance for malignancies
c. Ophthalmic care
What is Piebaldism?
a. Rare autosomal dominant condition
b. Characterized by a patch of white hair in the front (forelock)
c. Associated with patches of depigmented skin usually on the forehead
d. One of the cutaneous signs of Waardenburg syndrome
Management of Piebaldism?
a. Photoprotection
b. Skin surveillance
c. Camouflage with cosmetic cover creams
What is Tuberous sclerosis?
Autosomal dominant disorder that causes non-cancerous tumours to grow in various organs of the body
What genes are affected in Tuberous sclerosis?
TSC1 or TSC2 (codes for Hamartin and Tuberin respectively)
Both genes function as tumour suppressors
What are the skin manifestations in Tuberous sclerosis?
- Adenoma sebaceum
- Ashleaf spots (3 or more)
- Shagreen patches
What are Ashleaf spots?
Hypopigmented macules on the trunk and extremities associated with Tuberous sclerosis. This is apparent in infancy
What is a Shagreen patch?
This is a flesh-coloured plaque of skin in the lumbosacral region with an orange peel consistency. This is associated with Tuberous sclerosis and develops in childhood or early adolescence
What is adenoma sebaceum?
Reddish nodules in a butterfly pattern around the nose & cheeks; (facial angiofibroma)
Which benign tumours are associated with Tuberous sclerosis?
- Brain tumours (Giant cell astrocytoma which is most commonly subependymal)
- Cardiac rhabdomyosarcoma
- Renal cysts or renal angiomyolipoma
- Subungual fibromas
(True/False) Tuberous sclerosis is associated with infantile spasms or seizures?
True.
The greater number of brain tumours, the more severe the seizures
(True/False) Tuberous sclerosis is associated with intellectual disability?
True. This is due to brain lesions
Mx of Tuberous Sclerosis?
- Antiepileptics
- Removal of angiofibromas (Laser therapy)
- Tumours (Surgery/Chemo)
