Dermatology Flashcards
Langerhans cells
found where, function, derived from, granule shape and name
dendritic cells found in skin that act as professional antigen presenting cells, derived from the myeloid cell line and possess racquet shapped intracytoplasmic granules known as Birbeck granules.
Langhans cell
nuclei shape and number, derived from, function
multinucleated giant cell with horseshoe shaped arrangement of multiple nuclei derived from monocytic cell line, play role in granulomatous inflammation.
Merkel cells-cell type, location, function, pathology example
neuroendocrine cells of the basal layer of epidermis, perception of touch, associated with Merkel cell carcinoma (a type of skin cancer)
Melanocytes germ cell layer, location, function, number in dark vs white skin ppl
neural crest cells the migrate to basal layer during embryogenesis, pigment producing cells. dark skin doesn’t increase number but means increased production of melanin.
monocytes- stimulated to become, function (liver, bone, CNS, kidney and lung)
stimulated to become macrophages, serve specialized function in different organs (liver-kupffer cells, bone-osteoclasts, CNS-microglia, kidney-mesagial cells, and lung-alveolar macrophages)
Chediak-Higashi syndrome- def and presenting symptoms
autosomal recessive disorder of neutrophil phagosome lysosome fusion
-neurological abnormalities (nystagmus), partial albinism (abnormal meanin storgae in melanocytes), and immunodeficiency due to defective neutrophil function.
Phenylketonuria-def, impaired conversion of what to what? presenting features
deficiency phenylalanine hydroxlyase
- impaired conversion of tyrosine to phenylalaine
- CNS abnormalities (mental retardation, developmental delay), albinsm, and mousy odor
Wiskott-Aldrish Syndrome-genetic inheretance, triad
X-linked
-immunodeficiency (both T and B lymphocyte disorder), eczema, and thrombocytopenia
which nucleotide enzyme is needed to make melanin in melanocytes? can result in?
tryrosinase
albinism
splice site mutations result in proteins that are (size, function, immune response)
- larger size (all introns not spliced out)
- altered function (improper folding)
- preserved immune reactivity (all exons are present)
skin lesion:
- hyperpigmented and not raised
- pigmented, raised, after trauma
- pigmented,raised, alters with menstrual cycle
- pigmented raised and applying pressure causes retraction “button hole sign”
- pigmented and raised
- no pigment and beneath skin
- ephelides (freckles)
- keloid
- accessory nipple
- cutaneous neurofibroma
- pigmented nevus
- lipoma
timing and symptoms of
- graft-T cell sensitization against host MHC antigens
- host T-cell sensitization against MHC antigens
- host T-cell sensitization against ABO antigens
- 1 week, graft versus host disease, skin (jaundice, desquamation), liver (increased AST,ALT alkaline phosphate and bilirubin) and GI (diarrhea, intestinal bleeding, abdomnial cramping, and ileus)
- can be acute=vasculitis of great vessels or chronic=fibrosis of graft stroma and blood vessels
- acute (minutes), spasm and occlusion of graft vessels, ischemia and necrosis
skin presentations (age, lesion characteristics, and associations) of gluten enteropathy vs atopic dermatitis (aka eczema)
- childhood disease. pruritus and erythematous, weeping/crusted papules and plaques in lichenifications in flexural distribution (neck, wrists, antecubital and poplitea fossae). associated with other atopic disease like allergic rhinitis and asthma
- adult disease. associated with dermatitis herpetiformis, clusters of pruritic vesicles and plaques on buttocks and extensor surfaces of extemities
skins disease with erythematous, well- demarcated papules and plaques with a silvery scale.
psoriasis
mech of disinfectant. is it sporicidal?
- alcohols (isopropanol, ethanol)
- chlorhexidine
- hydrogen peroxide
- iodine
- disruption of cell membranes, denaturation of proteins; no
- disruption of cell membranes coagulation of cytoplasm; no
- produces destructive free radicals that oxidize cellular components; yea
- halogenation of proteins and nucleic acids; yes
which antibiotics are effective against pseudomonas?
- anti-pseudomonal
- cephalosporins
- aminoglycosides
- fluoroquinolones
- monobactams
- carbapenems
- ticarcillin and piperacillin
- ceftazidime (3rd gen) or cefepime (4th gen)
- amikacin, gentamicin, tobromycin
- ciprofloxacin and levofloxacin
- aztreonam
- imipenem and meropenem
Nikolsky’s sign, associated toxin and bacteria and pt pop
skin slipping off with gentle pressure
- S. aureus
- exfoilatin
- children and infants
Hartnup disease vs Fanconi syndrome
- loss of neutral amino acids
- generalized aminoaciduria
Hartnup disease presentation and treatment
- most of clinical presentation is due to loss of tryptophane a precursor for niacin, serotonin, and melatonin
- waxing and waning symptoms of photosensitivity, pellagra like skin rashes, ataxia.
- give niacin (nicotinamide+vit amine V3) or nicotinamide and high protein diet
which vitamin can be of benefit to measles infection?
vitamin A
what do nucleoside analogues require that nucleosides don’t in order to be effective? give examples of both types?
- sides require a viral cellular kinase
- tides already have their phosphate group attached and do not require viral kinase
- Tides-cidofovir, tenofovir
- Sides-acyclovir, valacyclovir, famiciclovir, ganciclovir
- mech of drugs used to treat psoriasis
- Calcipotriene
- Cyclosporine
- Etanercept
- MTX
- Ustekinumab
- topical vit D analog (aka calcipitriol) that bind vit D recetor and inhibits keratinocyte proliferation and stimulate keratinocyte differentiation
- inhibits NFAT (nuclear factor of activated T cells) from entering nucleus and modulating activity (imparing production of IL-2 which activates T cells)
- recombinate form of TNF that binds to TNF-alpha
- foalte antimetabolite that targets rapidly growing cells in skin
- human monoclonal antibodties that targets IL-12k IL-23 to inhibit t cell differentiation and actication
mutation in melanoma
- BRAF is a protein kinase involved in activation of signaling pathways for melanocyte proliferation
- it is mutated V600E in 50% if pt
gland found where/ function
- apocrine
- holocrine
- eccrine aka merocine
- paracrine
- dermis and subcutaneous fat of breast areloae, axillae and genital regions. sweat into hair follicles usually odorless but become malodorus secondary to bac decomposition
- associated with sebaceous glands, discharge of entire secretory cell
- in skin expect for lips and glans penis. Na and Cl- rich sweat direct onto skin
- similar to endocrine glands. reach target cells by diffusion instead of circulation
mc cause of hair loss? inheritance?
androgenic alopecia
- in both men and females
- polygenic inheritance with variable penetrance
name some common conditions influenced by multiple genes (CNS-3, Cardio-2, Endo-1, Derm-1, Onc-1)
androgenic alopecia epilepsy ischemic heart disease schizophrenia glaucoma HTN malignancy type II DM
axillary node dissection is a risk factor for? can lead to what sarcoma?
- chronic lympadema
- angiosarcoma (Stewart-Treves Syndrome)
- multiple firm violaceous (purple) nodules
structure of tRNA
- acceptor stem
- 3’ end contains?
- D arm
- anticodon arm
- T arm
- 5’ end contains?
- paris of 5’ and 3’ terminal nucleotides. helps to mediate correct tRNA recognictions and amitoacyl tRNA synthetase
- CCA is added as a postranslation modification
- contains numerous dihydrouracil residues
- sequences complemetary to mRNA codon and is read in 3’ to 5’ direction
- thymidine, pseudouridine, and cytidine residues
- terminal phosphate
which is only RNA molecule with thymidine?
tRNA
marjolin’s ulcer
example of malignant transformation.
-SCC that presents in area of previously tramatized, chronically inflammed or scarred skin.
more than 10yrs
what is excessive granulation formation. pt pop, histo
- keloids
- african americans
- haphazard arrangement of thick, pink collagen bindles
complication of VZV infection
- in thoracic dermatone
- trigeminal nerve?
- post-herpetic neuralgia
- visual impairment
penicillinase resistant penicillins are used to treat? not used for?
- nafcillin, methicillin, and oxacillin are used to treat S.aureus (foliculitis and abceesses) and s.epidermis
- not MRSA
- treatment for male patterned baldness
- tinea capitis
- alopecia areata
- finasteride (5-alpha reductase inhibitor)
- terbinafine (oral antifungal) b/c topical agents do not penetrate hair
- corticosteroids
how does RPR work? what is used to test for? confirm with what test?
take pt serum and place in solution of cardiolipin, cholesterol, and lecthin
- looks for antibodies that body forms in an attempt to fight syphillus (positive test will show “flocculation aka aggregation”)
- confirm with FTA-ABS
P bodies
-distinct foci found within cytoplasm of eukaryotic cells involved in mRMA regulation and turnover and storage
how is 5’ postranscription modification occur?
- addition of guanine triphosphate to 5’ end catalyzed by guanylyltranferase
- methylation of guanosine cap by guanine-7methyltransferase
histological appearance of VZV
-intranuclear inclusions in keratinocytes and multinucleate giant cells (Tzanck smear)
acantholysis
loss of intracellular connections
acantholysis form suprabasal blisters. disease? IF finding? antibody towards?
pempigus vulgaris
IgG deposits in reticular pattern
-desmoglein 4
accumulations of neutrophils on tips of dermal papillae (microabscesses)
-dermatitis herpetiformis
cytoplasmic vacuoles in keratinocytes (kiolocytosis) and hyperplasia of epidermis
-HPV infection
eosinophilic cytoplasmic inclusions (molluscum bodies) in infected cells and dome-shaped umbilicated papules
-molluscum contagiosum, a poxvirus
local cutaneous adverse effects of chronic topical corticosteroids
- atrophy and thinning of dermis
- loss of dermal collagen, drying, cracking, tightening of skin, telangiectasias, and ecchymoses
basal cell atypia, hyperatosis and parakeratosis? not basal cell carcinoma because?
- this explains actinic keratosis (hyperplasia of stratum cornenum (hyperkaratosis), abnormal retention of cellular nuclei in stratum coreum (parakeatosis))
- this is assocaited with SCC not basal cell
- basal cell presents as pearly papules with central depression
- histo theu have nest of basaloid cells and peripheral palisading of nuclei
benign proliferation of fibroblasts, solitary nodules, lower extremeties
dermoatofibroma
histological presentation of psoriasis
-clubbed rete ridges, hyperkeratosis, neutrophils in stratum corneum and perivascular lymphocytic infiltrates
gross appearance of Kaposi sarcoma
- lesions on extremeties head and neck
- palpable and dark brown to violet color
common complication of psoriasis
deforming joint disease (psoriatic arthritis)
presentation of survy
impair collagen formation (no vitamin C) leads to hemorrhages, subperiosteal hematomas, bleeding into joint spaces, gingival swelling, secondary periodontal infection, anemia, hyperkarototic papular rashes, impair wound healing, weakened immune response to local infections
mech of terbinafine
-inhibits fungal erogsterol synthesis by suppressing action of squalene poxidase
therapy precautions in isotretinoin (2) and use
systemic treatment of severe acne
-can cause teratogen and hypertriglyceridemia
vitiligo vs lentigo
- nested loss of epidermal melanocyte (flat well circumscribed macules and patches of absent pigment)
- benign linear (not nested) melanocytc hyperplasia
febrile rash in non immunized child that begins on face can be what viruses (families)? how to tell them apart?
- can be rubeola (measles) paramyxovirus or rubella (german measles)
- rubella also has postauricular lymphadenopathy
histoloical image of lipid laden macrophages from eyelid is? associated with what?
- xanthelasma
- primary or secondary hyperlipidemia
- cholestatc conditions like primary biliary cirrhosis can cause this
how does aging affect synthesis of collagen? does not do what?
- decreases it’s synthesis and net loss of dermal collagen and elastin
- does not impair collagen cross-linking
keloid formation
results from excessive colagen formation during wound repair
-soft or firm nodules that grow beyond boarders of wounds in claw like extensions into normal tissue
PABA (para-aminobenzoic acid) protects against which type of UV rays? what about aveobenzone? zinc containing sunscreens?
- only UVB
- UVAI and UVAII
- UVB, UVAI, and UVAII
antibodies against transglutaminase can result in what dermatologic manifestation?
dermatitis herpeformis
can antibody seen in celiac sprue
presentation of pemphigus vulgaris vs bullous pemphigoid
- antibodies against desmosomal proteins 3 and 1 leading to bullae and erosions of skin and mucosal membranes
- autoantibody against hemidesmosomal proteins leading to skin leisions
asboe sign and nikolsky sign associated with?
-bullae spread laterally with pressure
-new bullae form with gentle traction
signs of pemphigus vulgaris
thickening and hyperpigmentation of skin in flexural areas with “velvety texture”
acanthosis nigricans
-assocaited with insulin resistance states (DM, acromegaly, obesity) and GI malignancies (if appearance occurs suddenly)
pneumocytis infections results from B cell or T cell def?
T cell
what cells are active in the cell mediate immune response?
macrophages, CD4+, CD8+, and T-lymphocytes and NK cells
describe psoriasis-growth (4), layers affected (2), PE sign
- hyperparakeratosis, ancathosis, rete ridge elongation, mitotic activity above epidermial basal cell layer and a
- reduced or absent stratum granuosum but enlarged stratum spinosum
- neutrophils may form spongiotic clusters in superficial dermis and parakertotic stratum corneum (Munro microabscesses)
- Auspitz sign- pinpoint bleeding when scaler are scraped off
describe dermatitis herpetiformis (4), location, deposits where? associations (1)
- puritic papules, vesicles, and bullae
- elbows
- IgA deposits at tips of dermal papillae
- associated with celiac disease
histological changes in urticaria?
-superficial dermal edema and lymphatic channel dilation
no epidermal changes
acute onset of a spectrum of lesions (papules, urticarial plaques, blisters, targets)
erythema multiforme
- infections (HSV-if target lesions)
- drugs (sulfa, beta lactams, phenytoin)
what is responsible for retraction of overlying skin seen in breast cancer? not dermal lymphatic obstruction b/c?
- Cooper Ligament infiltration
- this is associated with peau-d’orange
cell response in tuberculoid leprosy vs lepromatous leprosy
- strong CD4+ cells response, presents with hypopigmented plaques due to bac growth restriction (like in Tubueruloid mycobacterium)
- weak CD4+ cell response (caseous necrosis)
seborrheic keratosis vs actinic kertosis
- flat, greasy, “stuck on” deeply pigmented. Leser-Trelat sign (indication of GI or lymphoid malignancy if multiple lesions occur at once)
- “sand-paper” like texture, brownish papules or plaques, due to sun exposure
lichen panus
5 Ps
- polygonal, planr, pruritic, purplish plaques on wrists, hands, trunk , and legs
- whitish reticular lines if mucosal involvement (Wickham)
most important prognostic factor is horizontal growth in malignant melanoma. T or F
False,
it’s vertical growth (Breslow thickness)
spongiosis
epidermal accumulation of edematous fluid in intercellular spaces
associaited with eczematous dermatitis
-increased thickness of stratum conrenum
associated diseases
hyperkaratosis
psoriasis and calluses
hyperkaraotsis with retention of nuclei in stratum corneum?
associtated diseases?
psoriasis
separation of epidermal cells
acantholysis;pempigus vulgaris
epidermal hyperplasia (increased spinosum)
acanthosis; acanthosis nigricans
petichiae vs purpura vs ecchymoses. which blanches?
1cm
these do not blanch
teleangiectasias (small) blanch
lentigos
small tan or brown macules (flat <1cm) most often seen on the sun exposed skin of middle aged or elderly.
