This Month in JAAD: July 2021

In this issue of the JAAD, McMahon et al (page 46) report on 414 cutaneous reactions after Moderna and Pfizer COVID-19 vaccination reported to the COVID-19 registry. The registry is a valuable international resource to collect and report data on dermatologic manifestations of COVID-19 infection. We encourage readers to engage in reporting data to the registry.

Chiu et al (page 38) present data suggesting that extracutaneous manifestations of morphea are more likely when lesions are located on the anterior or superior aspects of the head, extensor extremities, or both extensor and flexor extremities, as well as in linear and mixed morphea subtypes. In a retrospective study, Kim et al (page 105) report that poor treatment response in morphea patients correlates with tissue eosinophils and basilar pigmentation, suggesting that these features should prompt close monitoring for disease progression and the possible need for more aggressive therapeutic intervention. Prasad et al (page 114) report that 4.6% of patients with linear morphea had oral involvement versus 2.4% of their entire cohort of patients with morphea. They also note that 10.3% of the patients with generalized morphea had genital involvement versus 3.7% of their entire cohort. Those with genital lesions had a later onset of disease compared to those with oral morphea (57 years old vs 11.5 years old) and were more frequently associated with extragenital lichen sclerosus (59.2% vs 5.6%). Their data suggest that we should pay particular attention to the possibility of oral morphea in younger patients with facial linear morphea and genital lesions in postmenopausal women with extragenital lichen sclerosus. Dermatopathologists are aware of the histologic overlap between lichen sclerosus and morphea. While both can have prominent edema and homogenization of superficial dermal collagen, morphea lacks the lymphoid band underlying the homogenized zone and has deeper lymphoplasmacytic infiltrates and collagen sclerosis.

Simpson et al (page 62) report data from a phase 3 trial of baricitinib in the treatment of moderate to severe atopic dermatitis, and Adalsteinsson et al (page 56) report data suggesting that metformin use is associated with a decreased risk of basal cell carcinoma development, even at low doses (odds ratio = 0.71). The multivariate odds ratios were calculated with 95% confidence intervals using conditional logistic regression analyses for the association between metformin and the risk of basal cell carcinoma and squamous cell carcinoma. Odds ratios are used to compare the relative odds of an outcome of interest given exposure to the variable of interest. The 95% confidence interval is used to estimate the precision of the odds ratio. A small confidence interval indicates a higher precision of the odds ratio. Unlike P value, confidence interval does not indicate a measure's statistical significance. The authors took care to avoid confounding variables, and their results suggest that metformin is worth further exploration as an intervention to reduce the incidence of basal cell carcinoma.

Conflicts of interest

None disclosed.