Urticaria, photosensitivities, hypersensitivity, vasculitis

Question 1

IgE mediated type 1 hypersensitivity

Answer 1

urticaria

Question 2

Mast cell is the primary mediator which causes inflammation of mast cells, histamine causes cell contraction with leaking through the cells leading to edema and vasodilation causes erythema

Answer 2

urticaria pathophysiology

Question 3

Wheals, edematous plaques, with white halos, general distribution, migrate and regess and last <24 hours

Answer 3

urticaria

Question 4

How to manage acute urticaria?

Answer 4

H1 blockers- cetirizine, levocetirizine, loratidine, then diphenhydramine, hydroxyzine
H2 blockers- famotidine, cimetidine
doxepin- for pruritus
avoid heat, spicy foods, use hypoallergenic products, otc gels for pruritus placed in regrigerator, apply to skin cold, cool bedroom, cool bath, avoid nsaids and alcohol

Question 5

overheating especially with exercise, itching and burning

Answer 5

cholinergic urticaria

Question 6

hives after water exposure

Answer 6

aquagenic urticaria

Question 7

Labwork for urticaria

Answer 7

thyroid
throat culture
punch with DIF

Question 8

igE immediate hypersensitivity

Answer 8

angioedema

Question 9

management of patients with non-anaphylaxis angioedema

Answer 9

h1 antihistamines certirizine (high dose) 20mg BID
glucocorticoid; prednisone 20-40mg daily for 7 days

Question 10

Darier signs

Answer 10

mastocytosis

Question 11

ingestion or activities that cause mast cell degranulation

nsaid, alcohol ingestion, anticholinergic, anesthetics, narcotics, polymyxin B sulfate

heat & friction

Answer 11

mastocytosis

Question 12

UVA/UVB mediated
CD4 + T lymphocytes
occurs early in season or with winter tropical vacays

occurs on sun exposed areas primarily the arms, v of chest, back of neck, SPARES THE FACE

papulovesicular, same distribution every time

Answer 12

PMLE

polymorphous light eruption

Question 13

how to dx and treat PMLE

Answer 13

punch biopsy

prevention with good sunblock and clothing, topical steroids, antihistamine, severe case may need oral steroids

Question 14

photosensitivity triggered by UV exposure
strong associated wth hep C, liver disease, and hemochromatosis

Answer 14

porphyria cutanea tarda

Question 15

patient complains of fragility especially hands with ulcers, scarring and milia, hypertrichosis, mottled brown pigment around the eye

Answer 15

PCT

Question 16

How to dx and manage pct

Answer 16

biopsy w/ DIF
CBC, porphyrins, hepatitis panel
24 HR URINE FOR PORPHYRINS

Question 17

WOOD LAMP FINDINGS FOR PORPHYRIA CUTANEA TARDA

Answer 17

BRIGHT PINK OR CORAL COLORED URINE

Question 18

What plants contain psoralen compounds that cause phytophotodermatitis

Answer 18

meadow grass, parsnip, limes, wild angelica, cow parsley, carrot, fig,sweet orance, bishop’s weed, hogweed, rue, and celery

Question 19

You should always suspect a Fixed Drug Reaction when you see….

Answer 19

well-demarcated hyperpigmented macules on the face (especially around the mouth) hand/fingers, genital

Question 20

If the patient has been on a medication for _______ it is unlikely the cause of DRESS

Answer 20

more than 3 months

Question 21

hypersensitivity reaction
often from IV vancomycin

cipro, amphotericin B & rifampin

Answer 21

usually occurs during infusion but may be delayed, extreme flushing and pruritus, angioedema, anaphylaxis

Question 22

inflammation of blood vessels resulting in narrowed or occluded vessels, severity

Answer 22

vasculitis

Question 23

non palpable purpura w/ Cayenne pepper appearance (leaky capillaries) Schamburg’s disease

Answer 23

capillaritis or pigmented purpura

Question 24

Palpable purpura, lesions can coalesce to cover large areas, at times can seem urticarial but lasts > 24 hours, lower extremities and buttocks

Answer 24

leukocytoclastic vasculitis

Question 25

what should you do if you suspect leukocytoclastic vasculitis

Answer 25

1st- skin biopsy which will reveal- inflammatory infiltrates composed of neutrophils w/ fibrinoid necrosis Next- if histology confirms- chest xray with lab work

Question 26

panniculitis bilateral symmetrical tender pink nodules which can be bruise like, typically on the lower extremities, usually transient but may last 2 years, may have fever and joint pain, occurs with crohns/UC, most common in patient's with sarcoidosis

Answer 26

erythema nodosum

Question 27

how to dx erythema nodosum

Answer 27

punch biopsy, must include subcutaeneous fat, CBC, throat culture

Question 28

how to treat erythema nodosum

Answer 28

1st line- nsaids, indomethacin, naproxen, postassium iodide 2nd line systemic or ILK compression stockings and elevation

Question 29

High risk bites

Answer 29

cat bites bites to hand/foot puncture/crush injury immunosuppresion delayed presentation proximity to vascular graft/prosthetic joint

Question 30

how to care for bite wounds:

Answer 30

C/S then irrigate and debride wound, do not close puncture wounds, do not close a high risk wound

Question 31

primary closure for a bite only if

Answer 31

bite on the face with concern for cosmesis, antibiotic prophylaxis, f/u in 24-48 hours for wound check, never use tissue adhesive to close wound.

Question 32

antibiotic choices for bites

Answer 32

prophylaxis 3-5 days empiric 5-14 days

Question 33

Treat animal bites with

Answer 33

mupirocin ointment TID Augmentin 875/125mg BID for 5-14 days Alternative- PCN & metro, docy and metro, bactrim and metro update tetanus assess for need for rabies prophylaxis

Question 34

how soon should you begin antibiotic therapy after an animal bite

Answer 34

within 8-12 hours of incident

Question 35

small papules in a cluster or linear pattern, usually found on legs & ankles, children experience urticaria

Answer 35

flea bites

Question 36

how to treat flea bites?

Answer 36

vacuum regularly, professional exterminator, tcs, burrows solution, antihistamine

Question 37

20 minutes to 2 hours after painless to sharp sting Mild redness, urticaria, cyanosis halo lesion with pale round area surrounded by a ring of erythema, patient may complain of ha, parathesias, n/v, htn, spasms

Answer 37

black widow bite analgesics, muscle relaxants, antiemetics tetanus prophylaxis antivenom safe (risk for anaphylaxis) intermittent ice application and elevation

Question 38

min to hours after a painless bite, a central blister, mottled blanched halo with surrounding redness/swelling, becomes necrotic 3-4 days later, severe pruritus and burning pain at bite site w/in 2-6 hours, expanding ulcerative necrosis

Answer 38

brown recluse tetanus intermittent ice application and elevation antibiotic if secondarily infected.

Question 39

30min to 36 hours after painless bite, a firm nodule with blisters/pus, sloughing may appear, patient will complain of memory impairment, ha, nausea, and fatigue

Answer 39

HOBO abx if needed tetanus prophylaxis intermittent application of ice and elevation

Question 40

Bee/wasp sting management

Answer 40

cold compress, remove stinger, tcs and antihistamine

Question 41

Avoid moveing/rubbing limb, fresh water, cold, ice, urination on area, alcohol on site, lemon juice, meat tenderizer if .....

Answer 41

marine sting

Question 42

what should you do if you acquire a marine sting

Answer 42

remove tentacle, vinegar/seawater/hotwater antivenom-box jelly tcs antihistamine

Question 43

1st 30 days: flu like symptoms, erythema migrans (bulls eye) dx and treat

Answer 43

LYME DISEASE If elisa +- <30 days of symptoms igM and IgG western blot If elisa -: >30 days just IgG prophylaxis- doxy 200mg PO, single dose w/in 72 hours of bite localized doxy 100mg PO BID x 10 days Amoxicillin 500mg TID x 14days

Question 44

generalized, intense pruritus, worse at night, erythematous papules, excoriations, burrows/threadlike, fine linear pattern, favors wrists, interdigital spaces, waist, genitalia, areolae and umbilicus, spares head and face.

Answer 44

Scabies TX with topical permetrin 5% for infants >2 months and pregnanc ivermectin 200mcg/kg PO single dose repeat in 1-2 weeks seal everything in bag for 3 days treat all household members, itching will persist weeks after treatment