Food Allergy-

Question 0

describe IgE mediated in terms of onset, cell types, common foods, & ssxs

Answer 0

rapid onset (mins to 2 hrs of ingestion) from mediators released from mast cells or basophils

foods: cow’s milk, egg, soy, wheat, tree nuts, peanuts, shellfish
ssxs: vary: dermatologic, ophthalmologic, GI, respiratory, CV, neurologic, n/v, cramping, diarrhea, flushing pruritis, edema, syncope

Question 1

what is needed to determine a food allergy? what are the two types of responses? what normally blocks a food allergy rxn? driven by what type of allergic rxn? hypothesized cause?

Answer 1

thorough hx to clarify type of rxn & culprit foods
includes: immunological/allergic & non-immunologic rxn
healthy gut immune sys typically blocks intact proteins & other antigens to enter the sys
drive by Th2 skewed response & cytokine release
hypothesized causes: better infant hygiene = less microbial exposure, decreased omega-3 & increased omega-6 fats, processed foods= less antioxidants, change in protein configuration

Question 2

describe non-IgE mediated food allergy d/os, types onset, & ssxs

Answer 2

subacute/chronic sxs in GI & or skin
often type III or type IV hypersensitivity rxns
delayed onset, hours to days after food is ingested
ssxs: chronic vomiting, diarrhea, reflux, failure to thrive, atopic dermatitis

Question 3

testing for food allergies?

Answer 3

skin tests (IgE), RAST (IgE), elimination/challenge diet, food diary

Question 4

what is non-immunologic adverse food rxn in terms of prevalence and examples

Answer 4

very common

anatomic conditions, malabsorption syndromes, GERD, toxic rxn, agents, contaminants, food aversions/phobias

Question 5

examples of small bowel tumors benign & serious

Answer 5

benign: leiomyoma, lipoma, neuromas, can cause distention, abd pain, bleeding & obstruction
serious: adenocarcinoma (Crohn’s), lymphoma (celiac), carcinoid, kaposi’s sarcoma

Question 6

what is a polyp of the colon & rectum? what are the 3 types?

Answer 6

small sessile or pedunculated mass of tissue, grows into lumen

1. non-neoplastic polyps (benign)
2. adenomas (precursor to CA)
3. polyposis syndromes: familial inherited (AD) or non-familial

Question 7

hyperplasticity of non-neoplastic polyps? other types?

Answer 7

hyperplastic usu <.5 cm in diameter, 90% of epithelial polyps
also: hamartomas, pseudopolyps, lipomas

Question 8

prevalence of adenomas? histological types? risk assoc w/?

Answer 8

precursor to CA
~10% of all colonic polyps
histological types: tubular, tubulovillous or villous adenomas
risk of malignant potential related to size & histological type

Question 9

2 types of polyposis syndromes? what is each? complications?

Answer 9

1. familial adenomatous polyposis: rare, hereditary,
   begins in childhood & involves entire colon, many asx, some rectal bleeding 100% HAVE CARCINOMA BY AGE 40, some have extracolonic ssxs such as osteomas of skull or mandible, sebaceous cysts, adenomas in other pars of GI
2. peutz-jeghers syndrome: AD, hamartomas in stomach, small bowel and colon, self-limiting, mucocutaneous pigmentation

Question 10

etiology of polyps of colon & rectum?

Answer 10

exposure to cig smoke, chronic EtOH intake, UC increases risk & pts w/ primary relatives with UC have increased risk, pts w/acromegaly have 3x increased risk, pts w/skin tags have 10-77% incidence of colon polyps, pts who have had pelvic radiation have 2-4x increased incidence of colon polyps

Question 11

Ssxs of polyps of colon or rectum?

Answer 11

2/3 of individuals >65 yo have at least one adenomatous polyp often multiple, occur most commonly in recut & sigmoid colon
asx or bleeding, abd pain dt partial obstruction, change in bowel habits, watery diarrhea w/large villous adenomas

Question 12

how common is colorectal CA? high where, low here? more common in what genders where? etiology of colorectal CA?

Answer 12

very common CA, #3 after lung, prostate/lung , breast
high in North america, western Europe, Australia, low in japan, south america, Africa
colon CA more common in females, rectum in males
etiology: low fiber, high fat & animal protein, esp beef w/prolonged transit time, intestinal flora produces carcinogens & transformation of adenomatous polyp

Question 13

9 RFs of colorectal CA?

Answer 13

1. > 40 yo
2. IBD: UC risk is 30% after 25 yrs, Crohn’s dz (4-10x risk)
3. familial polyposis (100% WILL DEVELOP)
4. family hx of 1 relative w/colon CA (3x CA risk)
5. personal hx of breast & female genital CA
6. acromegaly
7. hamartoma
8. septicemia from strep bovis infxn
9. smoking/alcohol

Question 14

ssxs of colorectal CA? if early? R colon? L colon? rectum? advanced?

Answer 14

early: asx
R colon: ascending & cecum, usu lg before any sxs, fatigue, SOB, angina, vague abd discomfort or palpable mass later, usu fungating, grow large & mb palpable, bleeding usu occult
L colon: descending & sigmoid, tends to encircle colon, diarrhea & constipation or alternating, tenesmus with BM, late pain dt partial obstruction, hematochezia or occult blood loss
rectum: gross blood w/defecation
advanced: wt loss, anorexia, malaise, jaundice, ascites, hepatomegaly, SCLN enlargement

Question 15

screening for colorectal CA? diagnostic labs? DI?

Answer 15

screening: fecal occult blood, colonoscopy, CT colonography, urinary indican test to measure metabolites of undigested proteins
diagnostic labs: hemoccult blood, CBC, liver enzymes, carcinomebryonic antigen elevated in 70% of CRC but not specific
DI: sigmoidoscopy, double contrast barium enema, colonoscopy

Question 16

forms of anorectal CA? RFs assoc with?

Answer 16

adenocarcinoma, SCC, BCC, lymphoma

RFs: HPV, fistulas, leukoplakia, lymphogranuloma, venereum, condyloma accuminata, anal intercourse

Question 17

7 anorectal d/o’s

Answer 17

hemorrhoids
anal fissure
anoretal abscess/fistula
pruritis ani
proctalgia fugax
proctitis
pilonidal dz

Question 18

what are hemorrhoids? RFs? complicated by what 3 things? prevalence?

Answer 18

clusters of vascular tissue, smooth muscle 7& overlying mucosa
often complicated by inflam, thrombosis & bleeding
~50% of adults, peaks btw 45-65 yo, M+F
RFs: diarrhea, pregnancy, childbirth, increased interabd pressure, heavy lifting, prolonged sitting or standing, valsalva maneuver, anal intercourse, low fiber/high fat diet

Question 19

sxs of internal hemorrhoids & location to be considered internal?

Answer 19

internal= above dentate line, no sensory innervation
most commonly painless bleeding w/ BM, bleed, prolapse & cause perianal itching & irritation, perianal pain by prolapse & spasm of sphincter complex, acute pain when incarcerated & strangulated, related to sphincter complex spasm

Question 20

ssxs of external hemorrhoids & definition to be an external hemorrhoid?

Answer 20

external= below dentate line, sensory innervation present
sxs in 2 ways:
1. acute thrombosis of underlying external hemorrhoidal vein, usu dt specific event, acute pain lasts 7014 d & resolves w/resolution of thrombosis
recurrence occurs ~ 40-50% of the time at the same site

2. cause trouble w/hygiene w/development of skin tags

Question 21

PE of hemorrhoids?

Answer 21

visualization if external, skin tags, DE to find internal (non-tender), anoscopy: pink/blue friable swellings of the mucosa

Question 22

what is an anal fissure?etiology?

Answer 22

acute linear midline tear in anal canal from dentate line to anal verge
mostly b/w 20-60 yo, in a child usu indicates sexual abuse
etiology: hard stool, chronic diarrhea, 10% of chronic are caused by childbirth, habitual use of cathartics, anal intercourse or DRE, hx of syphilis & other STIs, TB, leukemia, Crohn’s, previous anal surgery, HIV

Question 23

ssxs of an anal fissure?

Answer 23

rectal pain usu burning, cutting or tearing, painful defecation, spasm of anus, bloody stools (bright red), mucoid d/c, pruritis

Question 24

ddx of anal fissure?

Answer 24

diverticular dz, IBD, foreign body, syphilis, herpes simples, HIV/AIDS, peds: sexual abuse

Question 25

what are anorectal abscess/fistulas dt usu?

Answer 25

cryptoglandular dz infxn which obstructs anal glands at dentate line which if chronic can lead to a fistula between the anal canal and perianal external opening

Question 26

etiology of anorectal abscess/fistula?

Answer 26

hx of Crohn’s, leukemia,diverticulitis, foreign body rxns, actinomycosis, chlamydia, lymphogranuloma venereum, syphillis, TB, radiation exposure, HIV

Question 27

ssxs of anorectal abscess/fistula?

Answer 27

throbbing, constant perianal pain w/edema, erythema, recurrent malodorous perianal drainage, pruritis, recurrent abscesses, fever, pain occ resolves spontaneously w/reopening of a tract or formation of a new tract, pain more with sitting, moving, defecating, coughing, pain throbbing & constant

Question 28

what is pruritis ani? etiology?

Answer 28

anal and perianal itching
allergies, irritants to food, frequent diarrhea, loose stools or incontinence, parasites, microorganisms, hygiene, warmth 7 hyperhidrosis, dermatologic /o’s, oral abx, systemic dz, sexual abuse, hemorrhoids, skin tags, fissure, fistula

Question 29

hat is proctalgia fugax? RFs? ssxs? PE?

Answer 29

benign anorectal pain syndrome of uncertain cause, benign, spasm of levator ani & coccygeal muscles
RFs: low fiber diet & IBS
SSXs: recurrent episodes of sudden, severe cramping pain localized to anus or lower rectum, resolves completely, usu in middle of night, entirely pain free b/w episodes, often at night awakens pt, attacks are infrequent, mb in clusters then abate for long periods, assoc w/conditions include back pain, prostatitis, derepression
PE: pain mb reproduced w/DRE