MCM and HDM Topics

Question 1

What type of hypersensitivity is allergic rhinitis?

Answer 1

Type I (IgE Ab mediated)

Question 2

What are the signs and symptoms of allergic rhinitis?

Answer 2

Allergic conjunctivitis – Itchy, tearing, red conjunctiva and swelling with seasonal variation.
Allergic rhinitis –pale, boggy, blue nasal mucosa. Signs-Allergic salute, Allergic shiners, Dennie Morgan folds/lines
Atopic dermatitis (eczema) – “Itch that rashes” usually involves flexor creases. May start in infancy, facial itchy
rash.
GI – Diarrhea and cramping p exposure to allergen

Question 3

What are type II cytotoxic hypersensitivity disorders?

Answer 3

Antibody-mediated cytotoxic reaction that involves complement activation.

Complement activation with subsequent lysis, recruitment of inflammatory cell, NK cells, and autoantibodies against receptors.

Question 4

What is an Arthus reaction? When do you see it? How does it resolve?

Answer 4

Arthus reaction (type III hypersensitivity reaction)
Bird fanciers or Bird breeders lung – Pigeons, parakeets, fowl, rodents
Occurs 4-8hours after antigen exposure.
Acute reactions normally spontaneously resolve within 1-3 days. Can become chronic.

Question 5

What are type III hypersensitivities?

Answer 5

Deposition of circulating complexes of antigen bound to IgG or IgM in target tissue with subsequent complement
activation -> neutrophils/macrophages which damage tissues.

Question 6

What are two types of Arthus reactions?

Answer 6

Farmer’s Lung

Serum Sickness: fever, urticarial, generalized lymphadenopathy, arthritis, glomerularnephritis, and vasculitits.

Question 7

What are type IV hypersensitivity disorders?

Answer 7

T cell mediated = Cellular immunity, Antibodies are not required in any of these reactions.
CD4 helper cells participate in Delayed Reaction Hypersensitivity (DRH), CD8 cytotoxic T cells are cytolytic to target cells.

Question 8

What are two types of type IV hypersensitivity?

Answer 8

Poison ivy and PPD skin test for TB

Question 9

What might be found in a pt’s hx when they have rheumatoid arthritis?

Answer 9

Onset - any age, peaks between 30 and 50 years of age.
Women, smokers, and those with a family history of the disease are at higher risk.
RA typically presents with pain and stiffness in multiple joints, most often the wrists, proximal
interphalangeal joints, and metacarpophalangeal joints.
The distal interphalanges and lumbar spine are not typically impacted by RA.
Morning stiffness lasting more than one hour suggests an inflammatory etiology.

ROS: Patients may also present with systemic symptoms of fatigue, weight loss, and anemia.

Question 10

What is seen in the PE for rheumatoid arthritis?

Answer 10

Boggy swelling caused by synovitis may be visible or

subtle synovial thickening may be palpable on joint examination.

Question 11

What’s the first line of treatment for RA? Why is it important to treat early?

Answer 11

Methotrexate. Treating early can increase likelihood of sustained remission or the lowest disease activity possible.

Question 12

What do you see in children with Juvenile Rheumatoid Arthritis?

Answer 12

Painless joint inflammation and typically a limp if lower extremity is affected.

Question 13

How do you diagnose Juvenile Rhematoid Arthritis?

Answer 13

Chronic arthritis lasting six weeks in at least one joint and exclusion of other causes of symptoms in
a person under age 16.

Diagnosis of exclusion, lab tests neither rule in nor rule out. Diagnosis is essentially clinical.

Question 14

What is the primary morbidity associated with juvenile rhematoid arthritis?

Answer 14

Idiopathic inflammatory eye disease– an ophthalmologist should screen all children with arthritis.

Question 15

Who is most likely to get Systemic lupus erythematosus?

Answer 15

Twice as prevalent in black people, ten times more common in females

Question 16

What does someone with systemic lupus erythematosus complain of?

Answer 16

Typically recurrent, with periods of relative remission followed by flares
Most common symptoms: fatigue, weight loss, and fever without a focal infection. Others: arthralgia and myalgia

*Fatigue and Arthralgia are present in almost all patients with SLE.

ROS is multisystemic.

Question 17

What is the common symptom that makes one suspect systemic lupus erythematosus?

Answer 17

Butterfly rash.

Other signs: discoid rash, malar rash, unexplained seizures, photosensitivity.

Question 18

What is psoriasis? Who has it?

Answer 18

Chronic inflammatory skin condition.

Onset most likely between 15-30 years old. 1/3 have a first-degree relative with the condition.

Question 19

Does HIV trigger psoriasis?

Answer 19

No, but can exacerbate existing disease.

Question 20

What should you consider when you see a rash or nail pitting?

Answer 20

A joint exam to rule out RA

Question 21

How do you treat psoriasis?

Answer 21

Topical corticosteroids, vitamin D analogs, and tazarotene (Tazorac)
are effective treatments for mild psoriasis.
Systemic biologic therapies are effective treatments for moderate to
severe psoriasis.
Tumor necrosis factor inhibitors are effective treatments for
psoriatic arthritis.

Question 22

Most common type of hyperthyroidism in US?

Answer 22

Grave’s disease- autoimmune disorder in which thyroid-stimulating antibodies activate thyroid-stimulating hormone (TSH) receptors

Question 23

Risk factors for Graves disease?

Answer 23

Female sex and personal or family history of an autoimmune disorder.

Question 24

What are the most common manifestations of hyperthyroidism?

Answer 24

The resulting adrenergic symptoms (e.g., palpitations, heat intolerance, diaphoresis, tremor, stare [an appearance of a fixed look due to
retraction of eyelids], lid lag, hyperdefecation)

Question 25

What happens in chronic autoimmune thyroiditis (Hashimoto’s)? What are risk factors?

Answer 25

Thyroiditis is a general term that encompasses several clinical disorders characterized by inflammation of the thyroid gland.
Malfunctioning immune cells attack your thyroid, limiting its production of thyroid hormone production.
Patients typically present with/without a non-tender goiter, hypothyroidism, and an elevated thyroid peroxidase (TPO) antibody level.
-A frankly elevated TPO antibody level is more specific for Hashimoto thyroiditis

Risks: female, family history

Question 26

How do you treat Hashimoto thyroiditis?

Answer 26

Levothyroxine ameliorates the hypothyroidism and may reduce goiter size.

Question 27

What’s the most common type of primary immunodeficiency in children?

Answer 27

Antibody, combined B-cell and T-cell, phagocytic, and complement disorders are the most common types of 1ID.

Question 28

What do children with 1ID present with?

Answer 28

Children with these diseases tend to have bacterial or fungal infections with unusual organisms OR
Unusually severe and recurrent infections with common organisms.
Worldwide, antibody disorders are the most common type of 1ID disease.
Antibody disorders can be broadly characterized by the absence or presence of B cells.
When B cells are present, disorders are further characterized by whether the B cells are of normal quantity or quality.

Question 29

What’s the strongest predictor of 1ID?

Answer 29

Family history

Question 30

What’s the most common type of B-cell disorder in the US?

Answer 30

IgA deficiency, a type of hypogammaglobulinemia, which is a low or deficient levels of any of the immunoglobulins (IgG, IgA, IgM, IgE ), or by an abnormal response of immunoglobulins to vaccinations.

Question 31

What is characteristic of agammaglobulinemia (X-linked Bruton tyrosine kinase def)?

Answer 31

Born absent of B cells in peripheral and umbilical blood.
Exam – May not have tonsils and/or lymph nodes.
All Ig subclasses are decreased, absence of B cell lymphocyte subset analysis.

Question 32

When do T-Cell Disorders (1ID) typically present?

Answer 32

Early in life.

Diarrhea, failure to thrive, opportunistic infections, and severe routine infections in a child younger than three months should raise suspicion for SCID and/or HIV.

Question 33

What are phagocytic disorders? Which is the most common, and when is it diagnosed?

Answer 33

Phagocytic disorders are the result of abnormalities in neutrophils or monocytes.
Chronic granulomatous disease is the most common phagocytic disorder in the ESID registry. Usually diagnosed by five years of age, and is characterized by pneumonia, abscesses, suppurative adenitis, and gastrointestinal infections.
The first manifestation may be omphalitis (infection of umbilical stump) in infants.

Question 34

What can’t the phagocytic system kill in phagocytic disorders (1ID)?

Answer 34

Catalase-positive organisms

Question 35

What do complement disorders involve (1ID)?

Answer 35

Infections with encapsulated organisms

Question 36

What are some signs that a child has 1ID?

Answer 36

Recurrent serious infections in two or more sites. If in a single anatomic location, more likely to be an anatomic defect.

Question 37

If a 24 yo M/F presents with fever, sore throat, and malaise, what should you consider?

Answer 37

HIV/take a sexual history. HIV commonly misdiagnosed.

Other considerations: epstein-barr, influenza, strep, gastroenteritis, viral URI

Question 38

What may be noted in the PE of someone with HIV

Answer 38

Hepatosplenomegoly

Question 39

What does HIV resemble in newborns?

Answer 39

HIV clinically resembles a T-cell immunodeficiency disorders like SCID and should be considered in newborns and adolescents who present
with diarrhea, failure to thrive, and unusual opportunistic infections.

Question 40

How do you test for HIV?

Answer 40

HIV RNA “viral load”
p24 antigen- measures p24 core proteins
HIV ELISA- presence of antibody