Itch is a common symptom of skin conditions such as psoriasis (Elewski et al., 2019). The processing of itch-related information can be influenced by implicit processes such as biased avoidance tendencies (Silverberg et al., 2018; Verhoeven et al., 2006) and attentional biases (Evers et al., 2019; van Laarhoven et al., 2020), which can amplify the sensation of itch. These processes can especially affect those with chronic itch and their significant others (SOs), because they may be exposed to itch-related stimuli more often than the general public.

In September 2022, Agelopoulos et al. (2023) published an investigation on the density and distribution of intraepithelial sensory nerve fibers using pan-neuronal marker, protein gene product 9.5, in skin biopsies from patients with chronic nodular prurigo (CNPG), atopic dermatitis (AD), and brachioradial pruritus (BRP) and from healthy controls. In addition to a reduced number of intraepidermal nerve fibers in biopsies from all patients compared with those from healthy controls, different neuronal branching patterns were recognized in CNPG, BGP, and AD (Agelopoulos et al., 2023).

In their recent paper, Almet et al. (2023) provide a framework for the research community aiming to standardize single-cell datasets and find common terminology to more accurately describe cutaneous cell populations and functional cell states. More specifically, the authors propose to construct a Human Skin Cell Atlas mainly derived from single-cell RNA-sequencing studies as part of a worldwide consortium organized by and integrated into the Human Cell Atlas Initiative. As challenging as it may sound, such an undertaking is necessary and worthwhile because it will help to deconvolute complex datasets for the benefit of clarity and reproducibility in cutaneous research.

Hair shafts are formed by a special mode of keratinocyte (KC) differentiation (Harland and Plowman, 2018), which is characterized by the accumulation of hair keratins (keratin [K]31–K40, K81–K90) and keratin-associated proteins, cell death by cornification, and integration of the dead cells into the growing hair shaft (Jones et al., 2018) (Figure 1a). The death of hair KCs is associated with the breakdown of the nucleus and other organelles (Fischer et al., 2011; Jones et al., 2018). Autophagy is a major intracellular degradation process that is controlled by autophagy-related genes (Mizushima and Komatsu, 2011).

Innate lymphoid cells (ILCs) are essential players in the skin-associated immune system, nevertheless little is known about their proteomes and proteomic diversity. Here, we describe over 6,600 proteins constitutively expressed by ILC2s and ILC3s from healthy human skin and blood using state-of-the-art proteomics. Although the vast majority of proteins was expressed by both ILC subsets and in both compartments, the skin ILC2s and ILC3s were more distinct than their counterparts in blood. Only skin ILC3s expressed uniquely detected proteins.

A hair whorl is a patch of hair growing in a circular pattern around a point specified by hair follicle (HF) orientations (Ziering and Krenitsky, 2003). As an easily observed human trait, established between 10 and 16 weeks of gestation (Smith and Gong, 1973), scalp hair whorl pattern is typically defined by the whorl number (single or double whorl) and whorl direction (e.g., clockwise, counterclockwise, or diffuse) (Ziering and Krenitsky, 2003). Because atypical whorl patterns have been observed in patients with abnormal neurological development (Smith and Gong, 1973), understanding the genetic basis of whorl patterns may help to unravel important biological processes.