SUMMER-FALL SESSION NR 507 MIDTERM ACTUAL
EXAM WITH ANSWERS
Differentiating between the rash of a Type 1 vs Type 4
Reaction - answer-- Type 1: Immediate hypersensitivity
reactions, termed atopic dermatitis, are usually characterized
by widely distributed lesions.
- Type 4: Contact dermatitis (delayed hypersensitivity) consists
of lesions only at the site of contact with the allergen.
The key determinant is the timing of the rash:
-Type 1 = Immediate
-Type 4 = Delayed: Several days following contact, ex- poison
ivy
Type 1 Hypersensitivity Reaction - answer-- "Allergic reaction"
- Mediated by IgE.
- Inflammation d/t mast cell degranulation.
- Hay fever, hives (uticaria).
- Local s/s: itching, rash.
- Systemic: wheezing.
- Severe, systemic reaction: anaphylaxis: hypotension, severe
bronchoconstriction.
,- Main tx: epinephrine.
Type 2 Hypersensitivity Reaction - answer-- Cytotoxic
reaction; tissue specific
- Macrophages are the primary effectors cells involved
- Causes tissue damage or alters function
- Examples: 1) Grave's disease- example of altering thyroid
function, doesn't destroy thyroid tissue. 2) ABO
incompatibility- example of cell/tissue damage; severe
transfusion reaction occurs & the transfused erythrocytes are
destroyed by agglutination or complement-mediated lysis.
Difference between type 2 & 3 hypersensitivity reactions -
answer-- Type 2: organ specific; antibody binds to the antigen
on the cell surface.
- Type 3: not organ specific; antibody binds to soluble antigen
outside the cell surface that was released into the blood or
body fluids, and the complex is then deposited in the tissues.
Type 3 Hypersensitivity Reaction - answer-- Immune complex
- Antigen-antibody complex deposited in the tissues
- Neutrophils are the primary effector cell
- Causes autoimmune diseases
- Examples: rheumatoid arthritis (joints), systemic lupus
erythematosus (SLE, organs)
, Systemic Lupus Erythematosus (SLE) - answer-- Facial rash
confined to the cheeks (malar rash)
- Discoid rash (raised patches, scaling)
- Photosensitivity (skin rash d/t sunlight exposure)
- Oral or nasopharyngeal ulcers
- Hematologic disorders (hemolytic anemia, leukopenia,
lymphopenia, thrombocytopenia)
- Immunologic disorders
- Non-erosive arthritis of at least two peripheral joints
- Serositis (pleurisy, pericarditis)
- Renal disorder
- Neurologic disorders (seizures, psychosis)
- Presence of antinuclear antibody (ANA)
Autoimmunity - answer-- Can be familial: Affected family
members may not all develop the same disease, but several
members may have different disorders characterized by a
variety of hypersensitivity reactions (autoimmune and allergic
reactions).
Alloimmunity - answer-- General term used to describe when
an individual's immune system reacts against antigens on the
tissues of other members of the same species.
EXAM WITH ANSWERS
Differentiating between the rash of a Type 1 vs Type 4
Reaction - answer-- Type 1: Immediate hypersensitivity
reactions, termed atopic dermatitis, are usually characterized
by widely distributed lesions.
- Type 4: Contact dermatitis (delayed hypersensitivity) consists
of lesions only at the site of contact with the allergen.
The key determinant is the timing of the rash:
-Type 1 = Immediate
-Type 4 = Delayed: Several days following contact, ex- poison
ivy
Type 1 Hypersensitivity Reaction - answer-- "Allergic reaction"
- Mediated by IgE.
- Inflammation d/t mast cell degranulation.
- Hay fever, hives (uticaria).
- Local s/s: itching, rash.
- Systemic: wheezing.
- Severe, systemic reaction: anaphylaxis: hypotension, severe
bronchoconstriction.
,- Main tx: epinephrine.
Type 2 Hypersensitivity Reaction - answer-- Cytotoxic
reaction; tissue specific
- Macrophages are the primary effectors cells involved
- Causes tissue damage or alters function
- Examples: 1) Grave's disease- example of altering thyroid
function, doesn't destroy thyroid tissue. 2) ABO
incompatibility- example of cell/tissue damage; severe
transfusion reaction occurs & the transfused erythrocytes are
destroyed by agglutination or complement-mediated lysis.
Difference between type 2 & 3 hypersensitivity reactions -
answer-- Type 2: organ specific; antibody binds to the antigen
on the cell surface.
- Type 3: not organ specific; antibody binds to soluble antigen
outside the cell surface that was released into the blood or
body fluids, and the complex is then deposited in the tissues.
Type 3 Hypersensitivity Reaction - answer-- Immune complex
- Antigen-antibody complex deposited in the tissues
- Neutrophils are the primary effector cell
- Causes autoimmune diseases
- Examples: rheumatoid arthritis (joints), systemic lupus
erythematosus (SLE, organs)
, Systemic Lupus Erythematosus (SLE) - answer-- Facial rash
confined to the cheeks (malar rash)
- Discoid rash (raised patches, scaling)
- Photosensitivity (skin rash d/t sunlight exposure)
- Oral or nasopharyngeal ulcers
- Hematologic disorders (hemolytic anemia, leukopenia,
lymphopenia, thrombocytopenia)
- Immunologic disorders
- Non-erosive arthritis of at least two peripheral joints
- Serositis (pleurisy, pericarditis)
- Renal disorder
- Neurologic disorders (seizures, psychosis)
- Presence of antinuclear antibody (ANA)
Autoimmunity - answer-- Can be familial: Affected family
members may not all develop the same disease, but several
members may have different disorders characterized by a
variety of hypersensitivity reactions (autoimmune and allergic
reactions).
Alloimmunity - answer-- General term used to describe when
an individual's immune system reacts against antigens on the
tissues of other members of the same species.
