Cutaneous Manifestations of Internal Disease Flashcards
What causes NF-1, what chromosome is it on, and how do you remember dis?
Autosomal dominant mutation in tumor suppressor gene neurofibromin, a GTPase in the Ras pathway, on chromosome 17. Remember this because NF-1 is also called von Recklinghausen disease, and there are 17 letters in “von Recklinghausen”.
When do neurofibromas first begin appearing in NF-1 and how do they influence develpment? What do they look like?
First start appearing around puberty, there can be thousands of them -> pedunculated flesh-colored papules
Can lead to seizures, learning disabilities, and poor coordination
What is the first sign of NF-1?
Cafe-au-lait macules -> flat, light brown, homogenous macules
-> 99% of NF-1 patients have it before age 1
What is the most specific clinical finding for NF-1?
Crowe sign -> axillary or inguinal freckling
Where and when are plexiform neurofibromas formed? What do they look like?
They occur along peripheral nerves. They are usally formed congenitally.
Create large, tender masses with overlying hyperpigmentation / hypertrichosis. They feel like a bag of worms
What are optic gliomas and their complication?
They are a type of pilocytic astrocytoma in adults, and may lead to blindness
Why should blood pressure be monitored in patients with NF-1?
Children may develop renal artery stenosis
Adults may develop pheochromocytoma
What causes tuberous sclerosis?
Autosomal dominant mutations in tumor suppressors TSC1 and TSC2: hamartin and tuberin.
What are common dermatologic lesions seen in tuberous sclerosis?
Ash leaf spots
Angiofibromas
Ungual Fibromas
Shagreen Patches
What are Ash leaf spots and angiofibromas? How do you see Ash leaf spots better?
Ash leaf spots - Hypomelanotic macules, accentuated by Wood’s lamp
Angiofibromas - hamartomas of connective tissue / bloood vessels which appear as bumps on face, beginning in childhood and stabilizing by adulthood
What are ungual fibromas and Shagreen patches?
Ungual fibromas - tumors of the nailbed
Shagreen patches - Connective tissue hamartomas seen on trunk
What brain tumor are you at increased risk for with tuberous sclerosis?
Subependymal giant cell astrocytomas
What is factitial dermatitis? How do you tell this is what it is?
Psychiatric condition in which patients self-induce skin wounds and often deny it
Typically the lesions have geometric borders and bizarre distribution, and are easily reachable with your dominant hand
What are the three possible skin manifestations of sarcoidosis?
- Papular sarcoid
- Plaque sarcoid
- Lupus pernio
What is lupus pernio?
Yellow-red to rust colored papules, plaques, or nodules usually affecting the skin of the nose as well as rest of face.
What is erythema nodosum and where does it typically occur?
Painful, erythematous lesions of subcutaneous fat (panniculitis) usually seen on anterior shins.
What conditions are associated with erythema nodosum?
Most cases are idiopathic but:
- Group A Strep - commonly in children
- Sarcoidosis
- TB / coccidioido / histo
- Inflammatory bowel disease
- Leprosy
Basically, think group A strept + all the conditions which result in granulomatous inflammation
What is yellow nail syndrome associated with?
Yellow nails with no cuticles and transverse ridging
-> typically associated with bronchiectasis and pleural effusions
What does nail clubbing imply?
Underlying lung disease
What are classical signs of venous insufficiency?
Varicosities, edema, ulcers, hemosiderin pigmentation
Stasis dermatitis (mimics cellulitis) and lipodermatosclerosis may develop
How should you treat venous insufficiency and stasis dermatitis?
Venous insufficiency - compression stockings -> helps improve pitting edema and venous return
Stasis dermatitis -> Topic corticosteroids and moisturizers
What is lipodermatosclerosis and how will the leg appear?
Skin, subcutaneous fat, and deep fascia become progressively hardened (indurated)
-> inverted wine bottle appearance because lower part of leg below calf gets restricted
What is pyoderma gangrenosum and what condition is most associated?
Painful ulcer with a “rolled” border
-> initial lesion comes from a pustule or inflamed nodule which ulcerates
-> most associated with inflammatory bowel diseases, especially ulcerative colitis (Crohn’s is mostly associated with erythema nodosum)
How should pyoderma gangrenosum be treated?
Let them heal gradually, do not attempt to debride them!
Associated with “pathergy” -> enlargement of lesion with trauma
You’ve come across prurigo nodularis before. What condition is it most associated with?
Most common manifestation of renal disease (patients itch due to uremia)
- > pruritic nodules on arms and legs
- > can also be seen in liver disease due to jaundice causing itching
What are Lindsay nails also called, what are they, and in what disease are they found?
“Half and half” nails - proximal half of nail appears white, distal half is reddish-brown and does not blanch
Found in end stage renal disease.
What skin condition of ESRD is characterized by painful ulcers with a black eschar? What is the most common cause of death in these patients?
Calciphylaxis -> toxicity due to elevated calcium levels secondary to hyperparathyroidism in endstage renal disease
Most common cause of death is staph septicemia due to failure of wound care
What scleroderma-like condition does gadolinium contrast for MRI cause if given to patients with ESRD?
Nephrogenic Fibrosing Dermopathy
-> indurated plaques on lower extremities, associatd with yellow plaques. Face is spared.
What is acanthosis nigricans and where does it appear?
Epidermal hyperplasia causing elevated, hyperpigmented skin thickening. Appears especially in neck, axilla, and groin
What conditions are associated with acanthosis nigricans and how is their onset different?
Insulin resistance - i.e. diabetes, obesity, Cushing syndrome
Visceral malignancy - i.e. gastric adenocarcinoma -> much more rapid onset than insulin-resistance related
What ulcerating condition of the shins is associated with diabetes? Must diabetes be present?
Necrobiosis Lipoidica Diabeticorum
Diabetes need not be present, and glucose control will not clear NLD
What is granuloma annulare and where does it typically appear? What condition is it associated with?
Grouped papules in an annular configuration, often appearing on the backs of hands as an isolated lesion
Associated with diabetes, resolves spontaneously without treatment
What lesions typically appear in diabetes where triglyceride levels excess 3000 to 4000 mg/dL? Where?
Eruptive xanthomas
-> typically on extensor surfaces of extremities, buttocks, and hands
What skin changes is Graves’ disease associated with and why?
Pretibial myxedema, due to increased hyaluronic acid in the dermis
-> symmetric, non-pitting yellow-brown waxy papuules and plaques
What is polymorphic eruption of pregnancy?
Urticarial papules and plaques that appear within stretch markers during late third trimester
-> very pruritic rash that resolves spontaneously with birth
Where does pyogenic granuloma often occur and what condition must be ruled out?
Often occurs on the gums during pregnancy.
Need to rule out amelanotic melanoma
What is melasma? What causes it / what does it look like / where is it?
“Mask of pregnancy” - hyperpigmentated poorly demarcated patches, typically on the face. Can also be associated with oral contraceptive use.
What is telogen effluvium and when does it happen very commonly? How does it resolve?
Shedding / thinning of hairs as hair follicles enter the shedding (telogen) phase.
Often happens post-partum
Resolves spontaneously, there is no effective treatment, may take up to 18 months
Give five major cutaneous manifestations of dermatomyositis.
- Periungual telangiectasias
- Gottron’s papules - violaceous papules overlying finger joints
- Shawl sign - purple erythema of back of neck and posterior shoulders
- Heliotrope rash - periorbital erythema and edema
- Mechanics hands - scaly fissures and inflammatory changes of hands bilaterally
What malignancies is dermatomyositis associated with?
Ovarian, lung, colorectal, breast, and non-Hodgkin’s lymphoma
A patient has flushing episodes which last for about 30 minutes, often associated with dyspnea, abdominal cramping, and diarrhea. What do they most likely have and where is it?
Carcinoid tumor - most common malignancy of the small bowel
What skin condition is associated with glucagonoma? Where does it develop and what does it look like?
Necrolytic migratory erythema
Patches of erythema which can become flaccid bullae and desquamate, leaving a collarette of scaling
Tends to favor the flexural areas of groin, buttocks and thighs (intertriginous areas)
What condition may glucagonoma be misdiagnosed with? What will patients present with clinically (outside of skin manifestations)?
May be misdiagnosed as intertriginous dermatitis (like diaper rash for adults)
Adults present clinically with new onset diabetes
Why are malignancies associated with acanthosis nigrans?
Tumor growth activates insulin-like growth factors, which stimulates EGFRs -> epidermal hyperproliferation
These lesions parallel neoplastic progression and recurrence
What is the sign of Leser-Trelat?
Sudden appearance of multiple seborrheic keratoses
-> indicates underlying GI malignancies
