FPP/MSS Flashcards
Pemphigus vulgaris
Autoimmune blistering disease. Acquires. Rare. Effects the elderly. Caused by autoantibodies against desmosal proteins specifically desmoglein 1 and 3. This weakens the desmosomes and results in intraepidermal blistering. Flaccid blisters that quickly turn into erosions. Affects mucosal and cutaneous sites. Nikolsky sign is positive.
Ichthyosis vulgaris
“Fish scale” Common AD genetic condition. Caused by mutations in the profilaggrin gene that leads to a defective cornified envelop. Extremities, primarily the shin, are affected. Presents with dry skin, hyperlinear palms.
UV
Known to promote the development of skin cancers like basal cell carcinoma, squamous cell carcinoma, and melanoma.
UVC
200-280 nm. Absorbed by the ozone. Very little reaches earths surface.
UVB
280-320 nm. Penetrates the epidermis and superficial dermis. Causes erythema and sunburn.
UVA
320-400 nm. Penetrates the dermis. Causes tanning and photo aging.
SPF
A measure of the protection against UVB. SPF= MED(protected)/MED(unprotected).
Sunscreen (physical blockers)
zinc oxide, titanium oxide. Reflects and scatters light.
Sunscreen (chemical blockers)
PABA, oxybenzene, avobenzene. Absorbs UV light and converts it to heat.
Collagen in the skin
Primarily type 1 and type 3. During embryogenesis and wound healing there is an increase in type 3. Produced by fibroblasts.
Marfans syndrome
Caused by a mutation in the fibrillin gene. AD. MS: tall and thin body type, long limbs and fingers, scoliosis, flexible joints. Eye: myopia, ectopia lentis. Skin: striae. CV: Aortic aneurysms/dilations, mitral valve prolapse.
Ehlers Danlos syndrome
Caused by a variety of mutations that disrupt collagen production. Results in fragile skin, prone to scarring, flexible joints, arthritis, severe scoliosis, rupture of the blood vessels, intestines, and the uterus.
Morphea
Localized scleroderma. Acquired autoimmune disease characterized by sclerosis (thickening of collagen). Appears erythematous and as indurated plaques that slowly expand. Can leave behind fibrotic and atrophic scars and can cause some joint and neurological complications.
Systemic sclerosis
Acquired autoimmune disease. More common in middle aged women. CREST: calcinosis cutis, Raynauds, Esophageal dysmotility, Sclerodactyly, Telangiectasia. Diffuse systemic sclerosis: Widespread sclerosis, pulmonary fibrosis, renal failure, GI disease, cardiac disease.
Erythema nodosum
Inflammation of the subcutis layer. Presents as tender, red nodules that arise in the shins. Reactive panniculitis means EN was caused by wither strep pharyngitis, oral contraceptives, IBD, or a malignancy.
Bullous pemphigoid
Antibodies are directed towards the BP antigens 1 and 2 (BP230 and BP180). Results in subepidural blistering. Niklosky sign is negative.
Generalized atrophic benign epidermolysis bullosa (GABEB)
Due to an absent or decreased expression of type 17 collagen (BP180).
Laminin 332
Binds to hemidesmosomes on the basal keratinocyte and to type 7 collagen in the dermis providing adhesion between the two structures. Within the lamina densa.
Mucous membrane pemphigoid
Antibodies against laminin 332, BP 180, and integrins. Results in the development of scars, strictures, synechiae, and blindness.
Epidermal bullosa acquisita
Antibodies against type 7 collagen. Even slight trauma elicits blistering. Erosions and healing leaves behind atrophy, milia, scars, and pigmentation defects.
Inherited epidermolysis bullosa
EB simplex is due to keratin 5, 14. Junctional EB is due to laminin 332, BP180, integrins. Dystrophic EB is due to collagen type 7. Kindler syndrome is due to Kindlin 1.
Hair follicle
Hair bulb, isthmus, infundibulum.
Hair cycle
Growth phase: anagen. Transition phase: catogen. Resting phase: telogen.
Anorexia
Characterized by an abnormal increase in lanugo hair types.
Hirsutism
Characterized by an abnormal increase in terminal hair types.
Telogen effluvium
No patches. Stressor results in an increase in the number of hairs in the resting phase. Thus, more hairs are in growth arrest and are shedding. Occurs 3 months after the stressor and eventually returns to normal after the stressor is no longer present.
Alopecia areata
Autoimmune condition characterized by the sudden development of round, smooth patches of hair loss. Nail pits may also be seen. Alopecia totalis and alopecia universalis. Lack of erythema distinguishes it from tinea capitis.
Anagen effluvium
Characterized by hair loss due to medication- chemotherapy.
Acne vulgaris
Peaks in adolescence. Initially acne develops as a result of an increase in sebum production in combination with impaired shedding of the conreocytes results in plugging of the hair follicle- formation of a comedone. A plugged hair follicle can rupture (under the influence of p. acnes) resulting in inflammation.
Topical retinoids
Targets the comedone. Normalizes follicular keratinization. Causes expulsion of existing keratinaceous plugs and prevents the formation of new lesions.
Topical and oral antibiotics
Targets p. acnes preventing inflammation.
Oral contraceptives
Blocks the production of androgens.
Acne rosacea
Related to vascular hyperactivity. Presents with easy blushing developing into a reddened complexion triggered by an external stimuli like alcohol. Also characterized by erythematous papules and pustules. No comedones.
Tinea versicolor
Malassezia furfur. Warm/humid climate. Oval to round scaly patches with fine overlying scale. Hyper or hypo pigmented skin.
Vitiligo
Autoimmune T cell mediated disorder. Results in the destruction of melanocytes and depigmented patches. In affected skin the number of melanocytes is markedly diminished and even absent. Symmetric involvement, unpredictable course, and spontaneous repigmentation.
Oculocutaneous albinism
Inherited disorder that results in congenital absence or marked reduction of pigment in the skin, hair, eyes. Occurs as a result of defects in melanin production due to a defective tyrosinase. Patients are at an increased risk for skin cancers.
Melanocytic nevi
Due to benign proliferations of melanocytes. Junctional nevi: nests in the DEJ; flat. Compound nevi: nest in the DEJ and within the dermis. Intradermal nevi: nests within the dermis; raised.
Congenital melanocytic nevi (CMN)
Larger than acquired. Malignancy depends on ABCDE: Asymmetry, border, color, diameter, evolution.
Ephelides
Freckles. Occurs on sun exposed areas of the body and darkens with sun exposure.
Cafe au lait macules (CALM)
Well circumscribed uniformly light to dark brown macules or patches which typically appear in infancy. Flat, pigmented birthmarks. Caused by a collection of pigmented-producing melanocytes in the epidermis of the skin.
Solar lentigines
Tan to dark brown or black macule due to exposure to UV radiation. Seen later an life and are bigger, which distinguishes them from ephelides.
Dermal melanocytosis
Blue to gray patch over the lumbrosacral region.
Neurofibromatosis Type 1
AD. Caused by mutations in the NF1 gene encoding neurofibromin. Develop mutiple CALMs, axillary and inguinal freckling. Neurofibromas can develop within skin appearing as soft rubbery papules. Plexiform neurofibroma- “bag of worms”.
Tuberous sclerosis
AD. Results in benign tumor formation in multiple organs. Caused by mutations in TSC1 and TSC2, encoding hamartin and tuberin. Skin involvement is manifest as facial angiofibromas (telangiectactic papules. Periungual macules (ash leaf macules). Majority are new and spontaneous mutations.
Piebaldism
AD. Characterized by congenital patch of white hair (poliosis) and white areas on the skin due to an absence of melanocytes within the sites. Areas are stable, in contrast to vitiligo, which is typically progressive.
Waardenburg syndrome
AD/AR. Characterized by achromia (white color) of hair, skin, or both. Congenital deafness, partial or total heterochromia irides, medial eyebrow hyperplasia (unibrow), broad nasal root, dystopia canthorum. Can be associated with mutations in the Pax 3 gene.
Capillary malformations
Flat lesions composed of dilated capillaries. Port-wine stain: always present at birth. Tend to darken and thicken over time. Associated with increased levels of VEGF.
Sturge Weber syndrome
Capillary malformation (port wine stain) in the V1 distribution plus neuro defects. Results in seizures, developmental delay, migraines, glaucoma, and increased choroidal vascularity.
Hemangiomas
Relatively common benign vascular tumors. Composed of epithelial cells that line the blood and lymph vessels. They go through a growth phase and then involute. In contrast, capillary malformations remain flat.
PHACE syndrome
Posterior fossa brain malformations. Hemangiomas of the face. Arterial cerebrovascular anomalies. CV anomalies. Eye anomalies.
Congenital ectodermal dysplasia (ED)
X-linked. Characterized by developmental defects of the hair, teeth, nails, sweat glands, lens of the eyes.
Hypohidrotic ectodermal dysplasia
One type of ED caused by mutations in the ectodysplasin signaling pathway- EDA, EDAR, EDARADD- which provide instructions for making proteins that work together during embryonic development. Present with an impaired ability to sweat, peg teeth, sparse hair, thin skin, low-lying ears, flattened nasal bridge, square forehead.
Seborrheic keratosis
Benign and common lesion of the epithelium. Develop in the middle to elderly. Appear as brown to black waxy papules or plaques. Most common on the face, trunk, upper extremities.
Leser-trelat sign
Sudden onset of multiple seborrheic keratosis which can be associated with internal malignancy. Most commonly associated with adenocarcinoma of the stomach.
Actinic keratosis
Solar keratosis. Common lesion that develops as a result of chronic sun exposure. Represents a dysplastic condition. Presents as rough, erythematous, yellow/brown, scaly lesions in the middle to elderly. Remain stable or regress or 0.1-10% can become malignant- squamous cell carcinoma.
Squamous cell carcinoma
Common in older individuals. 20% of all skin cancers. UV radiation is the most common cause, but can also be caused by chronic ulcers, old burn scars, HPV, radiation, arsenic, immunosuppression. SCC in situ presents as a red scaly plaque. Invasive lesions tend to be nodular an may ulcerate. 5% of SCC develop an invasive component and of these 30% have metastatic potential. The likelihood of metastatic potential is related to the degree of invasion and the thickness of the lesion.
Keratoacanthoma
Variant of SCC believed to originate from the hair follicle. Pink papule or nodule with a central keratin plug. Grows rapidly over a period of 2-10 weeks. Occurs mainly on sun damaged skin. Some lesions resolve spontaneously while others can cause extensive local destruction. Proliferating epithelium is well-differentiated.
Basal cell carcinoma
Most common human cancer. Secondary to chronic cun exposure. Can be locally destructive. Slow growing tumore that rarely metastasizes. Associated with dysregulation of the shh and PTCH pathways. Presents as pink, pearly, papules with prominent arborizing subepidermal blood vessels (telangiectasia). Ulceration and erosion are common.
Melanocytic nevi (acquired vs congenital)
Melanocytes are normally present in the basal layer of the epidermis. They can increase with sun exposure (acquired nevi) or there can be an increased number from birth (congenital nevi).
Dysplastic nevi
May occur sporadically or in a familial form. Are typically larger than acquired nevi. Multiple dysplastic nevi can, but not always, predispose someone to melanoma.
Dysplastic nevus syndrome
Multiple dysplastic nevi (>80). Familial variant is AD with mutations in the CDKN2A gene. Patients have an increased risk of developing other neoplasms- pancreatic cancer.
Melanoma
Most serious form of skin cancer. Risk factors include: excessive exposure to UV, fair complexion, childhood sunburns, many dysplastic nevi, family hx, or old age. Most important clinical sign is a change in an existing nevus. ABDCE changes. Radial growth is not as concerning as vertical growth. Superficial type (back/extremities). Nodular type (vertical growth, poor prognosis). Lentigo maligna (head and neck). Acral lentiginous (palm, soles, nails, AA).