With these limitations in mind, I have found the Psoriasis Epidemiology Screening Tool (PEST) to be the most useful psoriatic arthritis screening tool. One study determined that the PEST has the best trade-off between sensitivity and specificity compared to 2 other psoriatic arthritis screening tools, the Psoriatic Arthritis Screening and Evaluation (PASE) and the Early Arthritis for Psoriatic Patients (EARP).8
The PEST is comprised of 5 questions: (1) Have you ever had a swollen joint (or joints)? (2) Has a doctor ever told you that you have arthritis? (3) Do your fingernails or toenails have holes or pits? (4) Have you had pain in your heel? (5) Have you had a finger or toe that was completely swollen and painful for no apparent reason? According to the PEST, a referral to a rheumatologist should be considered for patients answering yes to 3 or more questions, which is 97% sensitive and 79% specific for psoriatic arthritis.9 Patients who answer yes to fewer than 3 questions should still be referred to a rheumatologist if there is a strong clinical suspicion of psoriatic arthritis.10
The PEST can be accessed for free in 13 languages via the GRAPPA (Group for Research and Assessment of Psoriasis and Psoriatic Arthritis) app as well as downloaded for free from the National Psoriasis Foundation’s website (https://www.psoriasis.org/psa-screening/providers).
ALT-70 Differentiates Cellulitis From Pseudocellulitis
Overdiagnosing cellulitis in the United States has been estimated to result in up to 130,000 unnecessary hospitalizations and up to $515 million in avoidable health care spending.11 Dermatologists are in a unique position to help fix this issue. In one retrospective study of 1430 inpatient dermatology consultations, 74.32% of inpatients evaluated for presumed cellulitis by a dermatologist were instead diagnosed with a cellulitis mimicker (ie, pseudocellulitis), such as stasis dermatitis or contact dermatitis.12
The ALT-70 score was developed and prospectively validated to help differentiate lower extremity cellulitis from pseudocellulitis in adult patients in the emergency department (ED).13 In addition, the score has retrospectively been shown to function similarly in the inpatient setting when calculated at 24 and 48 hours after ED presentation.14 Although the ALT-70 score was designed for use by frontline clinicians prior to dermatology consultation, I also have found it helpful to calculate as a consultant, as it provides an objective measure of risk to communicate to the primary team in support of one diagnosis or another.