Developmental Mucocutaneous Diseases Flashcards
what are the 4 Developmental Mucocutaneous Diseases discussed in this section?
1) Ectodermal dysplasia
2) White sponge nevus
3) Peutz-Jeghers syndrome
4) Hereditary hemorrhagic telangiectasia
what is the most common, and well known, form of ectodermal dysplasia?
Hypohidrotic ectodermal dysplasia
what is the definition for “ectodermal dysplasia”?
Group of inherited disorders in which:
two or more ectodermally derived structures do not develop normally or fail to develop
what kinds of ectodermal structures can be effected by ectodermal dysplasia?
Skin, hair, nails, teeth or sweat glands
T/F: For ectodermal dysplasia, there are Several patterns of inheritance depending on the type
True
there are over over 170 different subtypes, each with its own inheritance pattern
what are the extra oral symptoms of Hypohidrotic E. D.?
Heat intolerance due to reduced sweat glands
Fine, sparse blonde hair, eyebrows, eyelashes
what are the oral effects of Hypohidrotic Ectodermal Dysplasia?
Oligodontia (lack of development of 6 or more teeth)
conical teeth
how is ectodermal dysplasia managed?
Genetic counseling
Prosthetic dental management – based on the specifics of the case
what are the prosthetic dental options for Ectodermal Dysplasia?
Dentures
Overdentures
Fixed appliances
Dental implants
what are the odds of 2 offspring both having Polygenetic Oligodontia?
1:100,000
What is the inheritance pattern for White Spot Nevus?
Autosomal dominant
White Sponge Nevus is a type of “_______________”, meaning its a genetically-determined skin disorder
genodermatosis
when is white spot nevus usually diagnosed?
Usually first noticed at birth or in early childhood, sometimes noticed first in adolescence
what defect causes white sponge nevus?
Due to a defect in the normal keratinization of the oral mucosa
keratins 4 and 13
what are the oral findings for white spot nevus?
1) Asymptomatic, thick, white appearance of the buccal mucosa bilaterally
2) other oral sites may be affected as well
3) Nasal, esophageal, laryngeal, anogenital mucosa may also be involved
When diagnosing White Spot Nevus, ______________ is sometimes more diagnostic than a biopsy sample
Exfoliative cytology
what are the histological characteristics of White Spot Nevus?
A) Biopsy shows parakeratosis with acanthosis (thickening of the spinous layer)
B) Epithelial cells often show perinuclear eosinophilic condensation of cytoplasm; pathognomonic, or unique to WSN
what is the treatment protocol for White Spot Nevus?
1) No treatment is necessary
2) Reassure the patient that this is a harmless condition
3) Good prognosis
______________ syndrome is a relatively rare, but well recognized condition that is usually inherited as an autosomal dominant trait
Peutz-Jeghers Syndrome
About ___% of Peutz-Jeghers syndrome may represent new mutations
35%
what gene is mutated in Peutz-Jeghers syndrome?
what does this gene do?
SKT11 gene is affected – encodes for a serine/threonine kinase
what is the prevalence of Peuzt-Jeghers syndrome?
about 1 in 100,000 – 200,000 births
name the clinical characteristics of Peuzt-Jeghers syndrome:
A) Usually noticed in childhood
B) Characterized by freckle-like lesions which develop on the hands, periorificial skin (mouth, nose, anus, genital region) and oral mucosa
C) Polyps develop in the GI tract, especially the jejunum and ileum
Peuzt-Jeghers syndrome can cause bowel obstruction due to _______________
intussusception
(“telescoping” of a proximal segment into a distal segment)
May self-correct but surgery is sometimes needed to prevent ischemic necrosis
patients with Peutz-Jeghers Syndrome have an increased susceptibility to cancer that is about _____ times greater than a control population
18 times
which forms of cancer are most common in Peutz-Jeghers syndrome?
GI, pancreas, male and female genital tract, breast and ovary
Histopathology of the GI polyps due to Peutz-Jeghers syndrome:
Gastrointestinal polyps appear as benign hamartomatous (tissues normally present in the affected part) growths of intestinal glandular epithelium
these are NOT precancerous (that would be gardeners syndrome)
what is the treatment protocol for Peutz-Jeghers?
Genetic counseling
Patients should be monitored for intussusception and for tumor development
what is the inheritance pattern for Hereditary Hemorrhagic Telangiectasia? how prevalent is the disease?
autosomal dominant disorder that is estimated to have a frequency of about 1 in 10,000
Hereditary Hemorrhagic Telangiectasia is caused by a mutation of what?
Due mutation of one of 2 different genes, both of which play a role in blood vessel wall integrity and share similar clinical features
____________ are small collections of dilated capillaries
Telangiectasias
what are the clinical characteristics of HHT?
Hereditary Hemorrhagic Telangiectasia
A) Frequent spontaneous epistaxis often is the initial clue to the diagnosis
B) Numerous 1-2 mm red papules that blanch with diascopy are noted on the oropharyngeal and nasal mucosae
where are Hereditary Hemorrhagic Telangiectasia lesions most often found?
Lesions are most common on vermilion zone of lips, tongue and buccal mucosa
T/F: HHT may involve the GI mucosa, genitourinary mucosa, and conjunctival mucosa
true
What % of Hereditary Hemorrhagic Telangiectasia patients have Atriovenous fistulas in their lungs? Liver? Brain?
lungs (30% of patients)
liver (30%)
brain (10-20%)
the diagnosis for Hereditary Hemorrhagic Telangiectasia depends on what 4 features?
Diagnosis can be made if patient has 3 of 4 features:
1) Recurrent spontaneous epistaxis
2) Telangiectasias of mucosa and skin
3) AV malformation involving the lung, liver or brain
4) Family history of HHT
what are the histopathological features of HHT?
Collection of thin-walled blood vessels in the superficial connective tissue
what is the general treatment protocol for Hereditary Hemorrhagic Telangiectasia?
(give for mild, moderate & severe)
Genetic counseling
Mild HHT – no treatment
Moderate HHT – selective cryotherapy or electrocautery of bothersome lesions
Severe – septal dermoplasty to prevent epistaxis
what component of Hereditary Hemorrhagic Telangiectasia would warrant the use of prophylactic antibiotics?
With AV fistula involving brain, prophylactic antibiotics before dental procedures that cause bacteremia have been suggested due to 1% prevalence of brain abscess in these patients
prognosis for Hereditary Hemorrhagic Telangiectasia:
Generally good, although 1-2% mortality is sometimes noted due to complications related to blood loss
If brain abscess develops, then 10% mortality can be anticipated, despite early diagnosis and appropriate treatment
