Alopecia Areata: Most Likely Diagnosis
The patchy, smooth bald spots without broken hairs, rash, or scalp changes in this 69-year-old male are most consistent with alopecia areata, an autoimmune condition that causes non-scarring hair loss in well-demarcated patches. 1, 2
Clinical Presentation Analysis
The key diagnostic features pointing to alopecia areata include:
- Patchy distribution that does not follow the typical male pattern baldness (androgenetic alopecia) pattern of frontal-temporal recession and vertex thinning 1, 3
- Smooth skin at the bald spots without scaling, erythema, or scarring 1
- Absence of broken hairs (which would suggest tinea capitis or trichotillomania) 3
- No recent medication changes ruling out drug-induced alopecia 1
- Two-month duration consistent with the typical presentation timeline of alopecia areata 3
Differential Diagnosis Considerations
While androgenetic alopecia (male pattern baldness) is the most common cause of hair loss in men and has been associated with coronary artery disease risk—particularly severe vertex baldness in younger men—this patient's presentation does not fit that pattern 1, 2. The meta-analysis by Yamada et al. showed vertex baldness carries a relative risk of 1.48 for CHD in severe cases, but this manifests as diffuse thinning rather than discrete patches 2.
Important caveat: This patient's significant cardiovascular history (CAD, prior MI based on clopidogrel use) and type 1 diabetes do place him at higher baseline risk, but these conditions are not causally related to his current hair loss pattern 4.
Medication Review
None of his current medications are typical causes of alopecia areata:
- Insulin (Humalog/lispro): Not associated with hair loss 4
- Gabapentin: Rarely associated with diffuse hair loss, not patchy 4
- Carvedilol: Beta-blockers can rarely cause diffuse alopecia, not patchy 4, 5
- Atorvastatin: Statins rarely cause diffuse telogen effluvium 4
- Clopidogrel: Not associated with alopecia 4
Associated Autoimmune Considerations
Alopecia areata is an autoimmune condition, and patients with type 1 diabetes have increased risk of other autoimmune disorders 4. This patient's type 1 diabetes increases the likelihood of alopecia areata as both share autoimmune pathophysiology 4.
Recommended Diagnostic Approach
Examine for specific findings:
- "Exclamation point" hairs at the periphery of patches (short broken hairs wider at the distal end) 3
- Nail pitting or trachyonychia (present in 10-20% of alopecia areata cases) 1
- Pull test at the margins (gentle hair pull should yield <3 hairs normally; >6 hairs suggests active disease) 3
- Scalp dermoscopy showing yellow dots, black dots, and broken hairs if available 1
Laboratory evaluation to consider:
- Thyroid function tests (TSH, free T4) given association with autoimmune thyroid disease 4
- Complete blood count to rule out iron deficiency 4
- Consider antinuclear antibodies if systemic autoimmune disease suspected 4
Prognosis and Management Implications
The prognosis for limited patchy alopecia areata is generally favorable, with spontaneous regrowth occurring in 50-80% of cases within one year 1, 3. However, extensive involvement, longer duration, and presence of other autoimmune conditions may predict more persistent disease 3.