Genoderms Flashcards
PXE gene + inheritance
ABCC6 - AR
Pathophysiology + histology of PXE
Abnormal mineralisation of tissues - calcification of elastic fibres (stain VVG + Von Kossa)
Histology - clumped/frayed/degenerate elastic fibres in dermis
Clinical features of PXE
Chicken are Mental - COGO
- chicken skin - begins teenage years cobblestone, yellow colour, neck, under clavicles, axillae, groin, abdomen, perineum, thighs
- can occur soft palate, gingival mucosa
- mental chin exaggerated
- Cardiovascular - calcification - claudication, HTN, atherosclerosis, aneurysm
- ocular - angioid (Bruch’s membrane), peau d’orange changes - can impact vision
- GIT - bleeding
- Obstetric - miscarriage (unconfirmed)
Subtypes Ehlers Danlos
I, II - classical COL5A1 III - hypermobile TNXB IV - vascular COL3A1 -- these are all AD then the rest are XL/AR....
Buschke-Ollendorf
Also known as dermatofibrosis lenticularis disseminata
AR inheritance - LEMD3
juvenile elastomas, collagenomas, osteopoikilosis, short stature, DM
COLD DEERS (hiding in the bush) - collagenomas, osteopoikilosis, LEMD3, deafness, DM, elastomas, eyes, recessive inheritance, short stature
Cowden Syndrome
PALPaTE and Feel Behind The GUM
- papillomatosis
- acral keratoses
- lipomas
- punctake PPK
- trichilemommas
- epidermoid cysts
- fibromas (storiform collagenomas)
- Breast Ca
- Thyroid Ca
- GIT Ca
- Uterine Ca
- melanoma
Epidermal naevus syndromes
Sebaceous Polyps Feel A Bit Pimply - CFCC
- schimmelpenning (linear naevus sebaceous)
- phacomatosis pigmentokeratotica (sebaceous naevus + naevus spilus)
- follicular naevus syndrome (ipsilateral cataracts, MSK, neurological)
- angora hair naevus syndrome (neuro)
- Becker’s naevus syndrome (ipsi breast hypoplasia)
- Proteus (PIK3A/AKT, slow flow vascular, lipomas, cerebriform connective tissue naevi)
- Cowden’s
- FGFR (neuro)
- CLOVES
- CHILD
Note that the majority of epidermal naevi in Blaschko distribution
Classification of epidermal naevi
Keratinocytic, sebaceous, follicular, eccrine/apocrine
What is the significance of epidermolytic subtype of keratinocytic naevi?
KRT1, 10 gene, may be gonadal involvement –> risk of child with epidermolytic ichthyosis
CHILD syndrome inheritence + features
XL dominant
Congenital Hemidysplasia, ichthyosis + limb defect
Sharp midline cut off w keratinocytic/ verrucous epidermal naevi
– 2 patterns - naevus is either lateralised or in Blaschko’s lines
CLOVES syndrome gene + features
PIK3CA (same as Klippel Trenauny)
Congenital lipomatus overgrowth, vascular malformation epidermal naevus, skeletal malformation
Classification of congenital melanocytic naevi?
Small < 1.5cm
Medium 11.5-20cm
Giant > 20cm
What are the 2 types of proliferative nodules in congenital melanocytic naevi?
- benign proliferating nodule (present at birth, symmetrical, well circumscribed, firm, uniform colour)
- neuroid proliferation (not present at birth, develop during childhood, grow slowly, poorly defined, can become pendulous)
What are the possible complications of CMN + how to assess risk?
Psychological/ cosmetic
Neurological
Melanoma
Rhabdomyosarcoma
Risk factors = multiple satellite lesions, > 40cm predicted adult size, posterior axial location
MRI w contrast before 6 months of age
Outline the assessment + Ix needed in an infant with > 2 CMN
Full history (particularly neurodevelopmental)
Full skin examination including palpation, lymph nodes
MRI w contrast before 6/12 of age
—- if normal, then anual clinical review unless new symptoms
—- if intraparenchymal, then risk of seizures/ ADHD etc but no further imaging monitoring required
—- all other MRI findings require interval monitoring
