M3: rheumatology Flashcards
types of allergic reactions
1: IgE mediated Allergic. 2: cytotoxic reaction (IgM or IgG antiBodies bind to surface antigens on normal tissue cells and cause complement cascade). 3: immune-Complex reactions from IgG or IgM antibody/antigen complexes leading to complement cascade. type IV: Delayed T cell type reaction. local inflammation and then secondary response in 2-3days.
allergy development
risks: microbial exposure, abx use, environmental/gut biome, diet, lack of breastfeeding, genetics. for rheumatic disorders, send labs: CRP, ESR< ferritin, platelets, pro cal, CBC, comp metabolic panel, UA. second line: ANAs, DNA, anti-Sm antibody, serum complement levels. anti-CCP.
Immune deficiency
Primitive (innate) immunity and adaptive (acquired). innate is skin, mucus membrane, cough reflex, phagocytes, etc. Pattern recognition receptors activate with contact with microbial products. macrophages and DCs work for adaptive immunity. neotrophils are primarily phagocytic. monocyte appear 1-7 hours post neutrophil infiltration. cytokines mediate innate/adaptive immunity and stimulate T lymphocyte formation. interleukins promote production of WBC, induce chemotaxis, and alter adhesion molecule expression on many cells. interferons protect against viral infection but don’t kill them.
Severe combined immunodeficiency
persistent thrush, failure to thrive, pneumonia, diarrhea, recurrent difficult to treat unusual infections
Wiskott Aldrich syndrome
thrombocytopenia, bloody stools, draining ears, atopic eczema, recurrent infections with encapsulated organisms, EBV-associated malignancy. PIDDs: unusual, frequent, recurrent infections. B cell disorders have current infections, T-cell have severe infections. onset <6mo (T cell) 12 mo + (B cell or secondary) between 6-12 mo combined.
warning signs of immunodeficiency
4+ new ear infections in 1 year; 2+ serious sinus infections in 1 year; 2+ months on abx with little effect; 2+ pneumonias in 1 year; failure to gain weight or grow normally; recurrent, deep skin/organ abscesses; persistent thrush; need for IV abx; 2+ deep-seated infections; family hx.
immunodeficiency s/s
small/absent cervical lymph nodes, adenoids, tonsils. low cupped ears. telangiectasia. low counts. low IgA. do CBC, immunoglobulins, may need to refer. higher risk oncology problems.
atopic dermatitis
eczema; chronic, pruritic, inflammatory disorder with acute and chronic skin issues. in school age, a/c and popliteal fossa; infants, face and extensor involvement. may have food allergies. impaired protective barrier so dryness, cracking, increased skin markings, lichenification, susceptibility to bacterial, viral, fungal infections; need daily moisturizer in Neo period to prevent. T-cell driven with IL-4 and IL-13 causing IgE elevations. abnormalities in histamine production, chemotaxis, monocytes, and cytokines. more water loss. aggravating factors: harsh soaps, heat, sweating, infections, stress, food allergies, dry skin. family history common. 1/3 cases start <3mo old as dry skin.
AD s/s
intense itching/redness, papule, vesicles, edema, serous discharge, crusts, dry skin, spared diaper area. chronic s/s: lichenification, xerosis; itch scratch itch cycle; worse in dry winter months or with that; sweating increases itchiness, often secondary staph infection. secondary infection with herpes simplex is a derm ER needing acyclovir. hyperpigmentation. may have atopic pleats (Extra groove in lower eyelid called Dennie lines; crease across upper bulb of nose. accentuated palmar/flexural creases, allergic shiners, mild facial pallor, dry hair. keratosis pillars.
AD dx/tx
history, recurring itchy rash; based on clinical findings. can do KOH. diff: other dermatitis, deficiencies of zinc/biotin, ichthyosis vulgarisms, psoriasis, scabies. tx: moisturizer after bath. then topical steroids with low-potency for maintenance and higher potency for exacerbations. non soap surfactants and synthetic detergents. eliminate triggers. tx secondary infections. nightly antihistamine can relieve nightly itching. TCPs reduce inflammation and itching. can have thinning of skin, striae, telangiectasia, hypertrichosis, adrenal axis suppression. ointments are best. thin layer. if large areas or occlusion, systemic absorption is greatly increased. PDE-4 inhibitors block conversion of cAMP to AMP. topical calcineurin inhibitors are second line: tacrolimus and pimecrolimus. higher rate of lymphoma. commonly cause itching, stinging, burning and can last 1 hour but decreases after a week. work on sensitive areas, but avoid sun.
Juvenile Idiopathic arthritis
persistent arthritis for 6+ weeks in a child <16 years old. environmental triggers: infection, abnormal hormones, trauma to joint. this disease responds to Anakinra.
JIA s/s
oligoarticular: <4 joints with persistent disease; may have morning limp; may have an ANA; can be persistent or extended. polyarticular: >5 joints during first 6mo with acute or insidious onset; rheumatoid vasculitis; slowing of growth, fatigue, low grade fever; involves large or small joints; RF neg and ANA +. RF + 2-3 months apart, likely 8-10 years old, rapidly progressive. systemic: arthritis >1 joint for 6 weeks and <16 y/o; fever 2 weeks and 3 days daily fever with afternoon spikes. may have fleeting salmon color rash with fever, hepatosplenomegaly, lymphadenopathy, high inflammatory markers, RF/ANA rarely +, usually significant anemia, thrombocytosis, elevated transaminase. Spondyloarthropathy: sacroiliac joint involvement with either tenderness or inflammatory lumbosacral pain. +HLA-B27.
JIA s/s continued
pain, joint stiffness worse in the morning and after rest , arthralgia during day; joint effusion and warmth; younger children may be irritable or have behavioral regression. decreased appetite, myalgia, nighttime joint pain, inactivity, failure to thrive. premature fusion of epiphyses, bony overgrowth, limb-length discrepancies. observe for gait abnormalities. swelling of joint with effusion or thickening; heat over inflamed joint and tenderness; loss of joint range of motion and function. nail pits, ciliary injection, fleeting salmon-color rash.
JIA dx
by exclusion; negative lab markers often; r/o Lyme disease. CBC, ESR, CRP, lyme testing, CMP, liver function tests, UA, ASO, complements. diff: Lyme, rheumatic fever, reactive arthritis, autoimmune diseases, IBD. thyroid disease. oncological issues. tx: referral. NSAIDs. rheumatologist: DMARDs like methotrexate, sulfasalazine, leflunomide. steroids, or intraarticular.
SLE
chronic, multisystem autoimmune disease with autoantibodies leading to aberrant immune function with presentation of self-antigens and defects in clearing debris. Damage to organs. strong genetic component. Environmental factors: OC use, pregnancy, microbial, temperate climates, UV light, hormonal changes in puberty, certain drugs (Hydralazine and procainamide), cigarettes. immune complexes with B and T cell activity, higher in asians, African Americans, hispanics, native Americans.
