MOCK BOARD REVIEW

Suzanne Granados, M.D.Dermatology Associates of Virginia, P.C.

Ewwww… you’ve got cooties…

a.k.a. infestations and insects

Amblyomma americanum(Lone Star Tick)

• RMSF (Ricketsia ricketsii)• Tularemia (Francisella tularensis)

Ixodes ticksNE & Mid-West: I. scapularis

Western U.S.: I. pacificusEurope: I. ricinus

• Lyme disease (Borrelia burgdoferi)• RMSF (R. rickettsii)- mouthpart visible from dorsum- no white markings on dorsal plate

Dermacentor variabilis(American dog tick)

• RMSF• Tularemia- mouthpart visible from dorsum (short & rounded)- white markings on dorsal plate

Cheyletiella

• Walking dandruff on cats & dogs

Chigger larva(Trombicula alfreddugesi)

• Chigger bites• Scrub typhus (Rickettsia tsutsugamushi)

Sarcopetes scabei

• Scabies

Pediculosis capitis

• Head lice

Pediculus humanus var. corporis(Body louse)

• Epidemic typhus (Rickettsia prowazekii)• Trench fever (Bartonella quintana)• Relapsing fever (Borrelia recurrentis)

Phthirus pubis

• Crabs / pubic lice

Xenopsylla cheopis(Rat flea)

• Endemic typhus (Rickettsia typhi)• Plague (Yersinia pestis)

Chrysops

• Loaisis (loa loa)• Tularemia

Reduviid(Assassin or kissing bug)

• Chagas’ disease (American trypanosome – T. cruzi)

Lutzomyia(Sandfly)

• Leishmaniasis (L. mexicana, L. braziliensis)• Oroya Fever / Carrion’s Disease (Bartonella bacilliformis)• Verruga peruana (Bartonella bacilliformis)

Similium(Blackfly)

• Painful bites •Onchocerciasis (Onchocerca volvulus)

Cimex lenticularis(Bedbug)

• Urticaria / insect bites

Loxosceles reclusa(Brown Recluse)

•“ Red, white, & blue” necrotic spider bite

Lycosidae(Wolf spider)

• Spider bite that releases histamine edema, erythema, necrotic eschar,

lymphangitis

Lactrodectus mactans(Black widow spider)

• Spider bite: α-latrotoxin massive Ach & NE release from presynaptic

motor endplate muscle fiber fatigue

Io caterpillar

Puss caterpillar

• Purpura in a grid-like pattern

Saddleback caterpillar

Glow-in-the-dark

a.k.a. immunofluorescence patterns and basement membrane zone

a. Lamina lucida

b. Hemidesmosome

c. Basal keratinocyte

d. Anchoring plaques

e. Anchoring fibrils

f. Anchoring filaments

g. Keratin intermediate filaments

h. Plasma membrane

i. Lamina densa

j. Sublamina densa region

• IgG in intercellular space

ANSWER: Pemphigus vulgaris

• Desmoglein 3 (130 kd)

• Desmoglein 1 (160 kd)

A: IgG & C3 at BMZ

B: salt-split skin

C: IIF on human salt-split skin

ANSWER: Bullous Pemphigoid

• BP Ag1 (230 kd) - intracellular

• BP Ag2 (180 kd) – extracellular

•C3 > IgG favors pemphigoid over LE

A: C3 along BMZ

B: “ “ on salt-split skin

ANSWER: EBA

• Can also have IgG

• If IgG > C3, favors lupus and EBA over pemphigoid dz’s

• Linear IgA at BMZ

ANSWER:Linear IgA disease / CBDC

• LAD-1 (97 kd): part of BP Ag2

• Granular IgA along DE jxn (can have C3)

ANSWER: Dermatitis herpetiformis

• C3 deposition in superficial dermal blood vessels

ANSWER: Leukocytoclastic vasculitis

A: Linear deposition of C3 along BMZ

B: C3 in granular pattern along BMZ

C: IgG in homogenous and shaggy pattern along BMZ

ANSWER: lupus erythematosus

ANA PATTERNS

A. HomogenousB. SpeckledC. NucleolarD. Anti-centromereE. Anti-d.s. DNA

HOMOGENOUS

• Diffuse bright green staining of nuclei• SLE (can monitor progression)

PERIPHERAL

• Rim pattern stains native DNA along nuclear membrane

• Most suggestive of SLE

SPECKLED

• Stains small globules = nucleoli• MCTD, SLE, scleroderma

NUCLEOLAR

• Photonegative of speckled pattern because it stains nucleolar RNA

• Progressive systemic sclerosis

ANTI-CENTROMERE

• Ab's to kinetochore / mitochondria on centromere

• Raynaud’s, local scleroderma (CREST-specific), PSS

ANTI-d.s. DNA

• SLE (ass’d with renal disease)