The INCORRECT Statement is B: "Psoriatic lesions never present with itching"
Statement B is definitively false—psoriatic lesions are frequently pruritic, and this is well-established in authoritative guidelines. 1
Analysis of Each Statement
Statement A: Family history of psoriasis is usually present
This is CORRECT. Psoriasis is described as "a genetic, systemic, inflammatory, chronic disorder" 1. The genetic component means family history is commonly present, though not universally required for diagnosis.
Statement B: Psoriatic lesions never present with itching
This is INCORRECT and the answer to the question. Multiple AAD/NPF guidelines explicitly state that psoriasis is "characterized by scaly, erythematous patches, papules, and plaques that are often pruritic" and may be "often severely pruritic" 1. The word "never" makes this statement categorically false.
Statement C: The nails may also be affected
This is CORRECT. Nail psoriasis (psoriatic onychodystrophy) occurs in approximately 50% of fingernails and 35% of toenails in all patients with psoriasis 1. Notably, up to 90% of patients with psoriatic arthritis have nail changes 1, making this particularly relevant to the case presented.
Statement D: Common sites include knees, elbows, and scalp
This is CORRECT. Guidelines consistently identify these as classic locations: "commonly involving the scalp, elbows, knees, and presacral region" 2, 3. The patient in this case has elbow involvement, which is typical.
Statement E: Increased prevalence of obesity and metabolic syndrome
This is CORRECT. Psoriasis is associated with "components of the metabolic syndrome such as diabetes, cardiovascular disease" 1. The 2019 AAD-NPF guidelines specifically address comorbidities including "metabolic syndrome," "diabetes," "obesity," and "dyslipidemia" 2. This association is well-documented and clinically significant for patient management 4.
Clinical Relevance to This Case
This 50-year-old woman with elbow psoriasis and inflammatory knee arthritis demonstrates:
- Typical distribution (elbows—statement D is correct)
- Psoriatic arthritis (inflammatory joint fluid confirms this)
- Need for nail examination (statement C—should be assessed given PsA)
- Metabolic screening indicated (statement E—comorbidities should be evaluated)
The key teaching point: Pruritus is a common and often severe symptom in psoriasis that significantly impacts quality of life 1. Never assume psoriatic lesions are non-pruritic.