Assessment Questions for Suspected SSRI Hypersensitivity Reaction
Medication History and Timing
Ask the patient detailed questions about their current and past SSRI exposure to establish temporal relationship and identify the culprit drug. 1
Which SSRI are you currently taking, and what is the exact dose? Document the specific medication name, dosage, and formulation 1
When did you start this SSRI? Establish the exact date or number of days/weeks since initiation 2
When did your symptoms first appear? Document the precise timing from drug initiation to symptom onset (hours, days, or weeks) 2
Have you taken this specific SSRI before? Prior exposure and tolerance history is critical for risk assessment 1, 2
Have you ever taken other SSRIs (fluoxetine, sertraline, paroxetine, citalopram, escitalopram)? Cross-reactivity between SSRIs may suggest a class effect 3
Did you have any reactions to previous SSRIs? A history of similar reactions to other SSRIs strongly suggests drug class hypersensitivity 3
Have you recently increased the dose or restarted the medication after a break? Dose changes and re-exposure can trigger reactions 4
Symptom Characterization
Systematically assess the type, severity, and distribution of symptoms to differentiate between mild hypersensitivity, severe cutaneous reactions, and life-threatening conditions like serotonin syndrome. 1, 5
Cutaneous Manifestations
Do you have a rash? Where is it located? Document distribution (trunk, limbs, face, palms, soles) 3
What does the rash look like? Characterize as morbilliform, urticarial, vesicular, or other patterns 3, 6
Is the rash itchy (pruritic)? Pruritus is common in SSRI-induced rashes 3
Do you have any blistering, skin peeling, or mucosal involvement (mouth, eyes, genitals)? These findings suggest severe reactions like Stevens-Johnson syndrome/toxic epidermal necrolysis 1
Systemic Symptoms
Do you have fever? Document temperature and pattern; fever suggests drug-induced hypersensitivity syndrome/DRESS 5
Do you have facial swelling, lip swelling, or tongue swelling (angioedema)? These indicate more severe hypersensitivity 1, 6
Are you experiencing any difficulty breathing, wheezing, or chest tightness? Respiratory symptoms suggest anaphylaxis or severe reaction 1, 6
Do you have any unusual feelings of agitation, confusion, or restlessness? These may indicate serotonin syndrome rather than simple hypersensitivity 1
Have you noticed muscle twitching, tremors, or jerking movements (myoclonus)? Myoclonus occurs in 57% of serotonin syndrome cases and is highly diagnostic 1
Are you experiencing excessive sweating, rapid heartbeat, or changes in blood pressure? Autonomic instability suggests serotonin syndrome 1
Do you have muscle rigidity or stiffness, particularly in your legs? Increased muscle tone with lower extremity predominance is characteristic of serotonin syndrome 1
Timing and Progression
How quickly did your symptoms develop after taking the medication? Immediate reactions (minutes to hours) suggest IgE-mediated hypersensitivity, while delayed reactions (days to weeks) suggest T-cell mediated reactions 6, 5
Are your symptoms getting worse, staying the same, or improving? Progressive symptoms require urgent intervention 1
Did you feel odd, uncomfortable, or have an urge to urinate or defecate before symptoms started? These prodromal symptoms can precede severe reactions 1
Concurrent Medications and Exposures
Identify all serotonergic agents and potential drug interactions, as polypharmacy significantly increases risk of serotonin syndrome. 1
What other medications are you currently taking? Document all prescription medications, including other antidepressants, pain medications (especially tramadol, meperidine), migraine medications (triptans), anti-nausea medications (ondansetron, metoclopramide), and antibiotics (linezolid) 1
Are you taking any over-the-counter medications, herbal supplements, or dietary supplements? St. John's wort, tryptophan, and certain supplements can increase serotonin levels 1
Have you recently started, stopped, or changed the dose of any other medications? Drug interactions may precipitate reactions 1
Are you taking any medications that could cause similar symptoms? Consider other causes of rash or systemic symptoms 1
Past Medical and Allergy History
Establish baseline risk factors and previous hypersensitivity reactions to guide risk stratification. 1, 2
Have you ever had an allergic reaction to any medication before? Document specific drugs and reaction types 1, 2
Do you have a history of drug allergies, particularly to sulfonamides or other antibiotics? Cross-sensitivity patterns may be relevant 1
Do you have any history of atopic conditions (asthma, eczema, hay fever)? Atopic status may influence hypersensitivity risk 1
Have you ever had Stevens-Johnson syndrome, toxic epidermal necrolysis, or severe drug reactions? Prior severe reactions increase risk 1
Do you have any autoimmune diseases or chronic medical conditions? These may complicate the clinical picture 5
Severity Assessment and Red Flags
Immediately identify life-threatening features requiring emergency intervention. 1
Are you having any difficulty breathing, throat tightness, or feeling like you can't get enough air? These indicate potential anaphylaxis 1, 6
Do you feel dizzy, lightheaded, or like you might pass out? Hypotension suggests severe reaction 1
Have you noticed any changes in your urine color or decreased urination? Renal involvement suggests severe systemic reaction 1, 5
Do you have severe abdominal pain, nausea, or vomiting? Gastrointestinal symptoms may indicate systemic involvement 5
Have you had any seizures or loss of consciousness? These are critical severity markers 1
What is your current temperature? Hyperthermia >41.1°C indicates severe serotonin syndrome requiring emergency management 1