Telogen effluvium (TE) is characterized by diffuse hair shedding 2‐3 months after a stressor, and COVID‐19 infection is potentially one such stressor. Those who were infected with the virus were under immense psychosocial and physiologic stress. We retrospectively reviewed electronic medical records of 552 patients who were evaluated by a Henry Ford Health System dermatologist between February 2020 and September 2020 and had a diagnosis of COVID‐19 infection. Ten patients were identified with TE attributed to COVID‐19 infection and described their presentations as a case series. For the ten patients selected, the mean age was 48.5 years old and 90% were female. Six of the patients were Black, one Middle Eastern, and three White. On average, the hair shedding began 50 days after the first symptom of COVID‐19 infection. About 80% of these patients were treated with antibiotics, systemic corticosteroids, and/or hydroxychloroquine for their COVID‐19 infection and 70% were hospitalized. The presentations of these patients suggest that COVID‐19 infection may be a significant trigger of TE. TE caused by hydroxychloroquine, azithromycin or other medications cannot be ruled out, and the global pandemic itself is a source of psychosocial stress. Further studies will be needed to understand the long‐term prevalence and prognosis of TE associated with COVID‐19 infection.

To test the hypothesis that imaging biomarkers are useful for evaluating in vivo rod photoreceptor cell responses to a mitochondrial protonophore. Methods Intraperitoneal injections of either the mitochondrial uncoupler 2,4 dinitrophenol (DNP) or saline were given to mice with either higher [129S6/eVTac (S6)] or lower [C57BL/6J (B6)] mitochondrial reserve capacities and were studied in dark or light. We measured: (i) the external limiting membrane-retinal pigment epithelium region thickness (ELM-RPE; OCT), which decreases substantially with upregulation of a pH-sensitive water removal co-transporter on the apical portion of the RPE, and (ii) the outer retina R1 (= 1/(spin lattice relaxation time (T1), an MRI parameter proportional to oxygen / free radical content. Results In darkness, baseline rod energy production and consumption are relatively high compared to that in light, and additional metabolic stimulation with DNP provoked thinning of the ELM-RPE region compared to saline injection in S6 mice; ELM-RPE thickness was unresponsive to DNP in B6 mice. Also, dark-adapted S6 mice given DNP showed a decrease in outer retina R1 values compared to saline injection in the inferior retina. In dark-adapted B6 mice, transretinal R1 values were unresponsive to DNP in superior and inferior regions. In light, with its relatively lower basal rod energy production and consumption, DNP caused ELM-RPE thinning in both S6 and B6 mice.

Purpose The phosphodiesterase inhibitor sildenafil is a promising treatment for neurodegenerative disease, but it can cause oxidative stress in photoreceptors ex vivo and degrade visual performance in humans. Here, we test the hypotheses that in wildtype mice sildenafil causes i) wide-spread photoreceptor oxidative stress in vivo that is linked with ii) impaired vision. Methods In dark or light-adapted C57BL/6 mice ± sildenafil treatment, the presence of oxidative stress was evaluated in retina laminae in vivo by QUEnch-assiSTed (QUEST) magnetic resonance imaging, in the subretinal space in vivo by QUEST optical coherence tomography, and in freshly excised retina by a dichlorofluorescein assay. Visual performance indices were also evaluated by QUEST optokinetic tracking. Results In light-adapted mice, 1 hr post-sildenafil administration, oxidative stress was most evident in the superior peripheral outer retina on both in vivo and ex vivo examinations; little evidence was noted for central retina oxidative stress in vivo and ex vivo. In dark-adapted mice 1 hr after sildenafil, no evidence for outer retina oxidative stress was found in vivo. Evidence for sildenafil-induced central retina rod cGMP accumulation was suggested as a panretinally thinner, dark-like subretinal space thickness in light-adapted mice at 1 hr but not 5 hr post-sildenafil. Cone-based visual performance was impaired by 5 hr post-sildenafil and not corrected with anti-oxidants; vision was normal at 1 hr and 24 hr post-sildenafil. Conclusions The sildenafil-induced spatiotemporal pattern of oxidative stress in photoreceptors dominated by rods was unrelated to impairment of cone-based visual performance in wildtype mice.

Background: PRAME (PReferentially expressed Antigen in MElanoma) is an antigen that shows marked overexpression in melanoma compared to normal skin melanocytes. PRAME immunohistochemistry has proven effective in distinguishing melanocytic nevi from melanoma, but it is unclear if it may be used to distinguish melanoma in situ from other benign pigmented lesions. In particular, differentiating from melanocytic hyperplasia in sun-damaged skin is sometimes clinically and histopathologically challenging. We hypothesized that PRAME staining of solar lentigo, sun-damaged skin, and melanoma in situ would aid in setting a threshold of positivity that could be useful in evaluating such conditions.Methods: We collected and stained typical examples of solar lentigo, melanoma in situ, and non-lesional sun-damaged skin by PRAME immunohistochemistry to assess a potential cutoff of PRAME positivity.Results: Solar lentigo and non-lesional sun-damaged skin had 10 or fewer PRAMEpositive cells per millimeter (mean 1.2), on the other hand melanoma in situ had at least 16 (mean 75.1).Conclusions: PRAME immunostaining appears sensitive and specific in the current series. This could be clinically useful for distinguishing melanoma in situ from benign melanocytic hyperplasia in sun-damaged skin. However, further studies are required to determine if 10 cells per millimeter is an acceptable threshold of positivity.

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Background: The umbilicus is a special and prominent scar on the abdomen, which obliterates the portal through which the omphalomesenteric duct connected the primitive gut to the yolk sac. Umbilical skin lesions are rare but diverse, rarely diagnosed by biopsy.Objectives: The study aimed to analyze the clinical and histopathologic features of umbilical skin lesions. Methods: We performed a retrospective analysis of patients who visited our institution for umbilical skin lesions from January 2008 to December 2019. Age, sex, clinical features, etiologies, and histopathological features were obtained from patients' medical records and photographs.Results: There were 41 cases of histologically confirmed umbilical diseases. Among them, 31 patients were female (75.6%). The lesions included hypertrophic scars (11/41), epidermal cysts (7/41), verruca (6/41), seborrheic keratosis (5/41), nevus (4/41), steatocystoma (2/41), and one each case of endometriosis, hidrocystoma, neurofibroma, soft fibroma, foreign body granuloma, tick bite and heterotopic gastric mucosa. Conclusion: The most common umbilical skin lesions were hypertrophic scars followed by increased number of laparoscopic surgeries. Compared with other previously reported studies, fewer umbilical biopsies have been done in relation with diagnosis of metastatic cancer in our study, which may be due to decreased incidence of advanced gastric cancer and the early detection of cancer through endoscopy and CT scan these days.

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