Most chilblains observed during the COVID-19 outbreak occur in patients who are negative for COVID-19 on polymerase chain reaction and serology testing.

BACKGROUND: Acral lesions, mainly chilblains, are the most frequently reported cutaneous lesions associated with COVID-19. In more than 80% of patients tested, nasopharyngeal swabs were negative on reverse transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2 when performed, and serology was generally not performed. METHODS: A national survey was launched on 30 March 2020 by the French Society of Dermatology asking physicians to report cases of skin manifestations in patients with suspected or confirmed COVID-19 by using a standardized questionnaire. We report the results for acral manifestations. RESULTS: We collected 311 cases of acral manifestations [58.5% women, median age 25.7 years (range 18-39)]. The most frequent clinical presentation (65%) was typical chilblains. In total, 93 cases (30%) showed clinical suspicion of COVID-19, 67 (22%) had only less specific infectious symptoms and 151 (49%) had no clinical signs preceding or during the course of acral lesions. Histology of skin biopsies was consistent with chilblains. Overall, 12 patients showed significant immunological abnormalities. Of the 150 (48%) patients who were tested, 10 patients were positive. Seven of 121 (6%) RT-PCR-tested patients were positive for SARS-CoV-2, and five of 75 (7%) serology-tested patients had IgG anti-SARS-CoV-2. Tested/untested patients or those with/without confirmed COVID-19 did not differ in age, sex, history or acral lesion clinical characteristics. CONCLUSIONS: The results of this survey do not rule out that SARS-CoV-2 could be directly responsible for some cases of chilblains, but we found no evidence of SARS-CoV-2 infection in the large majority of patients with acral lesions during the COVID-19 lockdown period in France. What is already known about this topic? About 1000 cases of acral lesions, mainly chilblains, were reported during the COVID-19 outbreak. Chilblains were reported to occur in young people within 2 weeks of infectious signs, which were mild when present. Most cases did not have COVID-19 confirmed by reverse transcription polymerase chain reaction (RT-PCR), and few serology results were available. What does this study add? Among 311 patients with acral lesions, mainly chilblains, during the COVID-19 lockdown period in France, the majority of patients tested had no evidence of SARS-CoV-2 infection. Overall, 70 of 75 patients were seronegative for SARS-Cov-2 serology and 114 of 121 patients were negative for SARS-CoV-2 RT-PCR.

Cutaneous adverse drug reaction to oral acetazolamide and skin tests.

BACKGROUND: Few cases of cutaneous adverse drug reactions (CADR) to oral acetazolamide, a non-antimicrobial sulfonamide, have been previously reported, and the interest of acetazolamide skin tests has never been studied. OBJECTIVES: We report a series of ten patients with oral acetazolamide CADR and skin tests. PATIENTS AND METHODS: The files of ten patients with CADR secondary to oral acetazolamide prescribed for cataract surgery in most cases referred between 2001 and 2011 in four French dermatology and allergy departments were retrospectively reviewed. Skin tests with acetazolamide were performed in nine patients and twelve controls. Other sulfonamides were tested in five of ten patients. RESULTS: Seven patients developed maculopapular exanthema and four had acute generalized exanthematous pustulosis. Patch tests were positive for 8/9 patients, prick tests for 2/4 and intradermal tests for 3/3. Patch and prick or intradermal test results were concordant in 2/3 positive subjects. Patch tests for other sulfonamides were negative, as were patch tests in controls. CONCLUSIONS: We report the largest series of CADR to oral acetazolamide (maculopapular exanthema or acute generalized exanthematous pustulosis). A drug eruption after cataract surgery should be investigated for accountability of acetazolamide. In view of this retrospective study, skin tests and particularly intradermal tests appear to be an important contribution to demonstrate accountability.

Clinicopathologic correlation in erythema multiforme and Stevens-Johnson syndrome.

BACKGROUND AND DESIGN: To confirm the recent hypothesis that the spectrum of severe erythema multiforme (EM) is actually composed of two different disorders, we retrospectively studied 38 such cases, particularly in regard to their histopathologic features. Based on photographs and a recent proposal, the cases were classified as EM major when the eruption consisted of typical or raised atypical target lesions located on the extremities and/or the face or as Stevens-Johnson syndrome when the eruption consisted of flat atypical target lesions or purpuric macules that were widespread or distributed on the trunk. The cases were also assessed for causal agent. A biopsy specimen was obtained in each case. Several histologic parameters were analyzed (and scored) without clinical data and correlated to the clinical pattern. These parameters were first studied in a global assessment and then in a detailed evaluation. RESULTS: The global assessment showed two different histological patterns: (1) a predominantly inflammatory pattern characterized by a lichenoid infiltrate and epidermal necrosis that mainly affected the basal layer; and (2) a predominantly necrotic pattern in which major epidermal necrosis and minimal inflammatory infiltration were found. The former pattern was associated with EM major, the latter with Stevens-Johnson syndrome (P < .001) and with drug-related cause (P < .001). The detailed evaluation showed also less epidermal necrosis, and more dermal inflammation, and more exocytosis in EM major. Conversely, there was more epidermal necrosis, less dermal inflammation, and less exocytosis in Stevens-Johnson syndrome. The difference was statistically significant for the inflammation and exocytosis. CONCLUSIONS: This study suggests that the two different symptomatologies in the spectrum of severe EM correlate with two different patterns of histopathologic changes. A prospective multicentered study should be conducted to definitively characterize these entities.