Key differential diagnosis

1. Hypothyroidism (myxedema)
   • Clues: fatigue, cold intolerance, weight gain, constipation, hoarse voice, dry coarse skin/hair, eyebrow thinning, bradycardia
   • Puffiness often nonpitting, especially periorbital/facial
2. Angioedema (histamine- or bradykinin-mediated)
   • Sudden swelling of face/lips/tongue, +/- urticaria/itch (histamine type)
   • ACE-inhibitor angioedema can occur even after long-term use
   • Airway symptoms are an emergency
3. Drug-related edema (non-angioedema)
   • Calcium channel blockers, NSAIDs, corticosteroids, thiazolidinediones, etc.
4. Renal disease / nephrotic syndrome
   • Periorbital swelling, dependent edema, frothy urine, proteinuria, hypoalbuminemia
5. Cardiac failure / systemic fluid overload
   • Facial swelling less specific, but consider with dyspnea, orthopnea, leg edema, raised JVP
6. Cushing syndrome / chronic steroid exposure
   • “Moon face,” skin thinning, easy bruising, proximal weakness, HTN, diabetes
7. Superior vena cava obstruction
   • Facial/neck swelling, venous distention, dyspnea/cough, worse when supine
8. Dermatologic-inflammatory causes
   • Contact dermatitis, dermatomyositis, rosacea variants, eosinophilic cellulitis, etc.
   • Usually erythema/rash/itch/tenderness present
9. Salivary/parotid disease, dental or facial infection
   • More focal/asymmetric, painful, sometimes fever
10. Connective tissue disease

• SLE, dermatomyositis, systemic sclerosis depending on associated signs

Initial workup (practical)

• History: onset (sudden vs gradual), progression, new drugs (especially ACE inhibitors), allergy exposure, dyspnea/voice change, systemic hypothyroid symptoms, renal/cardiac symptoms
• Exam: pitting vs nonpitting edema, periorbital predominance, urticaria/rash, tongue/lip swelling, thyroid signs, JVP/lung crackles, leg edema
• Labs: TSH, free T4, CBC, CMP, creatinine, LFTs, albumin, urinalysis +/- urine protein/creatinine ratio
• Consider: BNP, ECG/CXR/echo (if CHF suspected), complement/C1 inhibitor studies (recurrent angioedema without urticaria), ANA/myositis tests if autoimmune features

Red flags (urgent/emergency)

• Lip/tongue swelling, stridor, breathing difficulty, voice change
• Fever with painful facial swelling
• Rapidly progressive unilateral swelling, orbital pain/vision symptoms

Diagnosing Hypothyroidism — Best Approach

Step 1: Clinical Suspicion (History + Examination)

• Puffy face, edematous eyelids (nonpitting)
• Dry, cool, pale/yellowish skin (carotene accumulation)
• Bradycardia
• Goiter (if Hashimoto's thyroiditis)
• Delayed relaxation of deep tendon reflexes (highly specific)
• Hoarse/husky voice

Step 2: Laboratory Diagnosis — The Gold Standard

Primary Hypothyroidism (most common, >95% of cases)

TSH is the single best screening test. A normal TSH essentially excludes primary hypothyroidism.

Central (Secondary/Tertiary) Hypothyroidism (rare — pituitary/hypothalamic disease)

• fT4 ↓ Low + TSH low, normal, or mildly elevated in the context of pituitary disease confirms central hypothyroidism (Hormonal Replacement in Hypopituitarism in Adults, p. 2)

Step 3: Identify the Cause

Step 4: Additional Workup (for completeness)

Summary Algorithm for This Patient

69F + facial puffiness + dry skin
        ↓
Check TSH first
        ↓
TSH ↑  →  Check fT4
           ↓
      fT4 ↓  →  Overt Primary Hypothyroidism
      fT4 normal →  Subclinical Hypothyroidism
        ↓
Check Anti-TPO antibodies → likely Hashimoto's

Key Point for Elderly Patients

TSH / Free T4 / Free T3

• Can be drawn at any time of day, regardless of food intake
• Food does not significantly affect thyroid hormone levels

One Practical Caveat — Biotin interference

• Patients taking high-dose biotin supplements (common in elderly women for hair/nails) can cause falsely low TSH and falsely high fT4, mimicking hyperthyroidism
• Ask about biotin use; ideally stop biotin for 2–3 days before drawing thyroid tests

However, if ordering the additional workup alongside thyroid tests:

Thyroid is OUT — Here's What the Reports Show

Re-Think the Diagnosis

Top Differential Now

🔴 1. Nephrotic Syndrome — Leading Diagnosis

"Clinically, patients present with generalized edema and, in contrast to heart failure with orthopnea, facial, eyelid and periorbital swelling is observed in nephrotic syndrome." (Harrison's Principles of Internal Medicine, 21e, p. 8392)

• Facial/periorbital puffiness is a hallmark — worse in the morning
• New hypertension fits perfectly
• Breathlessness can occur from pleural effusion or pulmonary edema
• Most common cause in elderly women: Membranous nephropathy (can be primary or paraneoplastic)

🔴 2. Early Congestive Heart Failure (HFpEF)

• Very common in elderly hypertensive women
• Facial swelling + exertional dyspnea + new HTN
• HFpEF (preserved EF) is the predominant type in this demographic

🟡 3. Central Hypothyroidism (rare but cannot fully exclude)

• TSH can be low-normal or normal with low fT4 in pituitary disease
• fT4 of 0.94 is at the very low end of normal
• If pituitary/hypothalamic disease suspected, this remains on the table (Hormonal Replacement in Hypopituitarism in Adults, p. 2)

🟡 4. Renal Failure / CKD with fluid retention

• HTN + edema + breathlessness — check creatinine, eGFR

🟡 5. Drug-induced (calcium channel blockers, NSAIDs, steroids)

• Always ask about medications

Urgent Next Investigations

Urine (Most Important First Step)

Blood

Imaging

Bottom Line

Nephrotic syndrome must be ruled out urgently with urine protein quantification and serum albumin. The combination of periorbital/facial edema (worse in morning), new hypertension, and exertional dyspnea in a 69-year-old woman fits this diagnosis closely. HFpEF runs a close second and can coexist.