Correlation of rosacea with hot beverage intake.

In this report, we correlated the incidence of rosacea with coffee (regular and decaffeinated) and tea consumption in a large cohort of middle-aged men and women living within the United Kingdom. Caffeinated coffee drinkers had lower odds for rosacea diagnosis compared to non-coffee drinkers. We hypothesize that the vasoconstrictive effects of caffeine in regular coffee overpower the vasodilatory effects associated with hot beverages and support it to be protective against rosacea.

Association Between Alopecia Areata and Natural Hair Color Among White Individuals.

IMPORTANCE: Alopecia areata (AA) is a complex immune-mediated disorder that causes nonscarring hair loss. Previous reports have documented preferential targeting of pigmented hair follicles with sparing of gray, nonpigmented hair follicles in alopecia lesions. Thus, immune targeting of melanogenesis-associated proteins in melanocytes and keratinocytes represents a potential mechanism for the inflammation that targets anagen hairs in alopecia areata. OBJECTIVE: To investigate the association of alopecia areata with hair color among White residents of the UK. DESIGN, SETTING, AND PARTICIPANTS: This matched, case-control study conducted in October 2020 used a large prospectively acquired cohort and included data that were collected from the UK Biobank, a large-scale prospective resource designed to study phenotypic and genotypic determinants in adults. A total of 502 510 UK Biobank participants were reviewed for inclusion. Among these individuals, 1673 cases of alopecia areata with reported hair color were captured and matched by age and sex to 6692 controls without alopecia areata using 1:4 matching. MAIN OUTCOMES AND MEASURES: Conditional logistic regression analysis was performed, in which the outcome variable was alopecia areata and the main predictor was natural hair color before graying. The variables considered included diabetes, hypothyroidism, hyperthyroidism, and vitiligo. RESULTS: Of 464 353 participants, 254 505 (54.8%) were women, and the mean (SD) age for those with alopecia areata was 46.9 (16.5) years. Alopecia areata was significantly more common in individuals with black (adjusted odds ratio [aOR], 2.97; 95% CI, 2.38-3.71) and dark brown hair (aOR, 1.26; 95% CI, 1.11-1.42) compared with light brown hair. In contrast, blond individuals exhibited significantly decreased alopecia areata compared with those with light brown hair (aOR, 0.69; 95% CI, 0.56-0.85). Red hair color was not significantly different from light brown hair. CONCLUSIONS AND RELEVANCE: The findings of this matched case-control study seem to indicate that alopecia areata is modulated by natural hair color, preferentially targeting darker hair. Our results support a previously proposed model of alopecia areata in which immunity is directed against melanogenesis-associated proteins in the anagen hair follicles. However, further study is needed to more precisely understand the immunopathogenic association between alopecia areata and hair color.

Hereditary Trichilemmal Cysts are Caused by Two Hits to the Same Copy of the Phospholipase C Delta 1 Gene (PLCD1).

The autosomal dominant presentation of trichilemmal cysts is one of the most common single gene familial diseases in humans. However, the genetic basis for the inheritance and genesis of these lesions has remained unknown. We first studied patients with multiple trichilemmal cysts using exome and Sanger sequencing. Remarkably, 21 of 21 trichilemmal cysts from 16 subjects all harbored a somatic p.S745L (c.2234 G > A) mutation in phospholipase C delta 1 (PLCD1), a proposed tumor suppressor gene. In addition to this specific somatic mutation in their tumors, 16 of the 17 subjects with multiple trichilemmal cysts were also heterozygous for a p.S460L (c.1379 G > A) germline variant in PLCD1 which is normally present in only about 6% of this population. The one patient of 17 that did not show the p.S460L germline variant had a germline p.E455K (c.1363 C > T) mutation in the same exon of PLCD1. Among 15 additional subjects, with a history suggesting a single sporadic trichilemmal cyst, six were likely familial due to the presence of the p.S460L germline variant. Of the remaining truly sporadic trichilemmal cysts that could be sequenced, only half showed the p.S745L somatic mutation in contrast to 100% of the familial cysts. Surprisingly, in contrast to Knudsen's two hit hypothesis, the p.S745L somatic mutation was always on the same chromosome as the p.S460L germline variant. Our results indicate that familial trichilemmal cysts is an autosomal dominant tumor syndrome resulting from two hits to the same allele of PLCD1 tumor suppressor gene. The c.1379 G > A base change and neighboring bases are consistent with a mutation caused by ultraviolet radiation. Our findings also indicate that approximately one-third of apparently sporadic trichilemmal cysts are actually familial with incomplete penetrance. Sequencing data suggests that the remaining, apparently sporadic, trichilemmal cysts are genetically distinct from familial cysts due to a lack of the germline mutations that underlie familial cysts and a decreased prevalence of the p.S745L somatic mutation relative to familial trichilemmal cysts.

Benign Glandular Schwannoma With Ancient Change.

Benign glandular schwannomas are rare and should be distinguished from malignant peripheral nerve sheath tumors with similar divergent tissue differentiation. The authors present a benign glandular schwannoma with ancient change that developed in the subcutis of a 46-year-old man's posterior calf. He lacked stigmata of neurofibromatosis type 1 (NF1). The glandular elements stained positively for epithelial membrane antigen and pancytokeratin. The spindled cells stained positively for SOX10 and S100 protein, supporting schwannian (neural crest) differentiation. The tumor's location and histopathology suggest that the pathogenesis stems from entrapment of sweat glands. Finally, it must be recognized that ancient change may mimic malignancy in these neoplasms as the malignant counterparts have a greater association with NF1 and a poorer prognosis.

Type I Cutaneous Meningioma (Rudimentary Meningocele) With Intradural Attachment to the Phylum Terminale.

Cutaneous meningiomas (CM) are a small subset of meningiomas, further classified into three subtypes. The authors present a 15-year-old male with a symptomatic congenital type I CM and describe the histopathological and immunohistochemical findings. To the authors' knowledge, this is the first report of an extraspinal lumbar type I CM with intradural attachment to the phylum terminale.