Annular Lichenoid Dermatitis of Youth: Its Pathogenesis, Diagnosis, and Management.

Annular lichenoid dermatitis of youth (ALDY) is a newly described controversial benign lichenoid inflammatory cutaneous disorder often characterized by annular patches with hypopigmented center and surrounding erythematous border. Primarily, it affects the trunk and groin of young patients. Since its first description in 2003, additional patients have been reported, leading to better characterization of the entity; nevertheless, the pathogenesis is still unclear, and several hypotheses have been provided about possible triggering or causative factors. It tends to follow a chronic course, with some lesions spontaneously remitting, while others may be persistent or recur post-treatment. No standard validated treatment has been indicated so far for this disorder. Commonly prescribed topical treatment includes corticosteroids and calcineurin inhibitors with variable response.

Erosive Pustular Dermatosis of the Scalp.

Erosive pustular dermatosis (EPD) is a rare entity, but it is generally overlooked or missed, rather than rarely encountered. It presents with erosions and shallow ulcers, accompanied by delayed healing and associated with cutaneous atrophy, rather than pustules. It exhibits predominance for women, with a predilection for a chronically sun-damaged scalp and, less commonly, the extremities, particularly the legs, as well as the face and mucosal surfaces. The role of infection, actinic damage, trauma, hormones, autoimmune disease, cutaneous atrophy, and genetics in the pathogenesis of EPD has been described in literature. Increased awareness and a high index of suspicion permit prompt treatment with topical corticosteroids, with or without oral zinc, followed by maintenance therapy with topical calcineurin inhibitors. Prevention, prior recognition, and prompt treatment are required for addressing this complex condition. (SKINmed. 2023;21:12-19).

Primary Localized Cutaneous Amyloidosis of Keratinocyte Origin: An Update with Emphasis on Atypical Clinical Variants.

Amyloid is a protein derived from at least 20 different substances. Once misfolded, it results in a group of cutaneous and systemic conditions. Primary localized cutaneous amyloidosis of keratinocyte origin is a very common subtype that can manifest either as lichen or macular amyloidosis, lacking systemic involvement. Lichen amyloidosis often presents as multiple hyperpigmented papules on the lower extremities whereas macular amyloidosis is classically characterized by dark brown rippled macules on the interscapular area. Review of the literature reveals that in addition to the classical presentation of primary localized cutaneous amyloidosis there exists a plethora of various manifestations that can be grouped into either geographic or morphologic categories. This review provides clinicians with the intimate knowledge of these presentations and summarizes the available treatment modalities.

Comparative characterization of sun exposed and sun protected skin-derived mesenchymal-like stem cells in variegate porphyria and healthy individuals.

BACKGROUND AND PURPOSE: We hypothesized that upon sun exposure, a sub-population of primary skin-derived mesenchymal-like cells is deleteriously affected and thus contribute to the chronic inflammatory state in autosomal recessive variegate porphyria patients. The aim of this study was to isolate and characterize the mesenchymal-like stem cells from different areas of the skin in a porphyria patient (sun exposed, SE, and sun protected, SP) and to compare them with cells from a healthy individual. METHODS: The proliferation rate and the migration ability of SE and SP cells were evaluated in the presence of an antioxidant compound, N-acetylcysteine. A co-culture of SE-damaged cells with the conditioned medium from the enriched mesenchymal cell-like SP population was performed in order to regenerate the dermal injured tissue after sun exposure in patients. RESULTS: Results showed that the percentage of CD105+ cells varies between 3.9% in SP and 5% in SE of the healthy individual and between 3.6% and 1.4% in SP and SE in the porphyria patient, respectively. The osteogenic differentiation potential was lower in the porphyria patient when compared to the control. Furthermore, the expression of stem cell markers was more pronounced in SE than in SP cells of both control and porphyria. The use of N-acetyl cysteine did not show any beneficial effects on porphyria SE cells. Treatment with SP-conditioned medium slightly increased the expression of stem cell markers in SE of porphyria patient. CONCLUSION: In conclusion, the pool of mesenchymal stem-like SE cells is affected in variegate porphyria patient along with modification of their self-renewal and differentiation properties.