Wolf's isotopic response: A case of dermatomal granuloma annulare after COVID-19 vaccination.

The SARS-CoV-2 pandemic was announced in March 2020, with the first vaccines becoming available later that year. Although generally well tolerated, there have been reports of skin reactions occurring after receiving COVID-19 vaccines, with a rare occurrence of granuloma annulare. Granuloma annulare can occur secondarily to herpes zoster infection in a phenomenon known as Wolf's isotopic response (WIR). WIR has been described to often occur after herpes zoster virus infection, at the location of the healed shingles rash, termed 'post-herpetic isotopic response' (PHIR). We present the first reported case of PHIR with granuloma annulare after the Moderna COVID-19 vaccination series. This reported reaction should not limit receipt of the COVID-19 vaccine, but awareness of this association can minimise additional work-up and treatment.

Elucidating the time course of the transcriptomic response to photobiomodulation through gene co-expression analysis.

Photobiomodulation (PBM) with low-intensity red to near infrared light elicits neuroprotection in various pre-clinical models and in some clinical contexts, yet the intracellular mechanisms triggered by PBM, and their temporal sequence of modulation, remain unclear. We aimed to address this uncertainty by mapping the temporal transcriptomic response to PBM. Human SH-SY5Y neuroblastoma cells were treated with 670 nm PBM and RNA collected a various time points over 24 h. The transcriptome was screened by RNA microarray, and gene co-expression analysis by hierarchical clustering was coupled with bioinformatics analysis to reveal the molecular systems modulated by PBM and their expression patterns over the time course. The findings suggest that PBM induces distinct early phase (up to 8 h post-PBM) and late phase (24 h post-PBM) intracellular responses. The early intracellular response features enrichment of pathways relating to transcriptional regulation and cellular stress responses, while the late intracellular response demonstrates a physiological shift to enrichment of downstream pathways such as cell death and DNA damage. These findings provide support for the hypothesis that PBM acts as a transient stressful stimulus, activating endogenous stress response pathways that in turn enhance cellular resilience. Further, the study introduces a novel method for retaining the richness of the temporal component when analysing transcriptomic time course data sets.

Linear morphea overlying site of previous lichen aureus in a pediatric patient.

Lichen aureus is a pigmented purpuric dermatosis that tends to occur on the lower extremities, and linear morphea is an inflammatory disease of the dermis and subcutaneous fat that leads to a scarlike induration. We present a pediatric case of linear morphea developing in the same anatomic distribution as prior lichen aureus. Due to the possible progression of lichen aureus to morphea described herein and the difficulty in diagnosing early morphea, close follow-up may be considered for pediatric patients who present with this pigmented purpuric dermatosis.