(1) Background: Calcinosis of the skin mainly appears in connective tissue disorders (dystrophic subtype). It may cause inflammation, ulceration, pain, and restricted joint mobility. Management is difficult; sodium thiosulfate is one potential therapeutic agent with promising data on intralesional and topical formulation for smaller calcified lesions. There are very limited data on systemic administration. (2) Methods: A retrospective study was conducted at our department to assess the efficacy of oral and intravenous sodium thiosulfate in dystrophic calcinosis between 2003 and 2023. (3) Results: Seven patients were identified, who received systemic sodium thiosulfate (intravenous or oral). The mean duration of calcinosis at the time of administration was 3.8 ± 4 years (range 0–11). Intravenous sodium thiosulfate was administered in doses of 12.5–25 g two or three times during one week of the month for 4.5 ± 3.9 months on average. Orally, 1–8 g was administered daily for 29.1 ± 40.9 months on average. Four of seven patients had a partial response (57.1%). Despite no complete response, pain, ulceration and inflammation frequency decreased, and sodium thiosulfate prevented further progression in responsive patients. (4) Conclusions: Based on our experience and literature data, systemic sodium thiosulfate may be a potential adjunct therapy in calcinosis, especially if inflamed or ulcerating.

Calcinosis cutis is a heterotopic accumulation of calcium salts in the skin. It has been described as a late-onset complication of burn scars in a few cases, in contrast to heterotopic ossification, which may be an early-onset complication of burn injuries. Diagnosis of calcinosis can be confirmed by radiography, ultrasonography, computed tomography, magnetic resonance imaging or histology. Almost all cases of late-onset calcinosis in burn scars present as non-healing ulcers on the lower extremities near contracture bands. It has been hypothesized that this localization is due to the more frequent microtrauma of the lower extremities, and that ulceration is due to the presence of calcium deposits as foreign bodies. In our study, the mean age at the time of burn injury was 12.5 ± 8.27 years, and calcinosis developed after a mean time of 37.5 ± 14.95 years (mean age at onset was 50.5 ± 14.53 years). There was no significant difference between burn scars managed with skin grafting and those where skin grafting was not carried out. The ulcers healed after resection or extraction of the deposits without any recurrence at the same site. In contrast to previously reported cases, we observed two cases of non-ulcerating late-onset calcinosis in burn scars of the upper extremities.

Background/Objectives: Calcinosis cutis is the deposition of insoluble calcium salts, which may cause inflammation, ulceration, pain, and restricted joint mobility. It rarely develops in damaged tissues (dystrophic subtype), most frequently in autoimmune connective tissue diseases (CTDs), but there is very limited data on the prevalence. Also, therapy remains an unsolved issue. In this study, we aimed to collect data on the prevalence of calcinosis in CTD patients to highlight that it is a considerable problem. Methods: A retrospective study was conducted in our department to assess the epidemiology of dystrophic calcinosis in CTDs between January 2003 and January 2024. Results: A total of 839 CTD patients were identified, of whom 56 had calcinosis (6.67%). The mean age of the calcinosis patients at diagnosis of underlying CTD was 41.16 ± 19.47 years. The mean time interval from the onset of calcinosis was 5.96 ± 8.62 years. Systemic sclerosis was the most common CTD complicated by calcinosis (n = 22). Conclusions: Our results are comparable to those reported previously in the literature. Although calcinosis is rare in the overall population, it is a present and unsolved problem in CTD patients. Therefore, further studies are needed on the factors involved in the development and progression of calcinosis as well as its treatment.

Pseudoxanthoma elasticum (PXE (OMIM 264800)) is an autosomal recessive connective tissue disorder mainly caused by mutations in the ABCC6 gene. PXE results in ectopic calcification primarily in the skin, eye and blood vessels that can lead to blindness, peripheral arterial disease and stroke. Previous studies found correlation between macroscopic skin involvement and severe ophthalmological and cardiovascular complications. This study aimed to investigate correlation between skin calcification and systemic involvement in PXE. Ex vivo nonlinear microscopy (NLM) imaging was performed on formalin fixed, deparaffinized, unstained skin sections to assess the extent of skin calcification. The area affected by calcification (CA) in the dermis and density of calcification (CD) was calculated. From CA and CD, calcification score (CS) was determined. The number of affected typical and nontypical skin sites were counted. Phenodex + scores were determined. The relationship between the ophthalmological, cerebro- and cardiovascular and other systemic complications and CA, CD and CS, respectively, and skin involvement were analyzed. Regression models were built for adjustment to age and sex. We found significant correlation of CA with the number of affected typical skin sites (r = 0.48), the Phenodex + score (r = 0.435), extent of vessel involvement (V-score) (r = 0.434) and disease duration (r = 0.48). CD correlated significantly with V-score (r = 0.539). CA was significantly higher in patients with more severe eye (p = 0.04) and vascular (p = 0.005) complications. We found significantly higher CD in patients with higher V-score (p = 0.018), and with internal carotid artery hypoplasia (p = 0.045). Significant correlation was found between higher CA and the presence of macula atrophy (β = − 0.44, p = 0.032) and acneiform skin changes (β = 0.40, p = 0.047). Based on our results, the assessment of skin calcification pattern with nonlinear microscopy in PXE may be useful for clinicians to identify PXE patients who develop severe systemic complications.

Calcinosis cutis, die heterotope Ablagerung von Kalziumsalzen in der Haut, wurde in einigen Fällen als spät auftretende Komplikation von Brandnarben beschrieben. Sie unterscheidet sich diesbezüglich von heterotoper Ossifikation, die eine früh einsetzende Komplikation von Brandverletzungen sein kann. Die Diagnose einer Kalzinose kann radiographisch, sonographisch, computertomographisch, magnetresonanztomographisch oder histologisch bestätigt werden. Nahezu alle Fälle einer spätmanifesten Kalzinose bei Brandnarben imponieren als nicht heilendes Ulkus an den unteren Extremitäten in der Nähe der Kontrakturbänder. Es wird diskutiert, dass diese Lokalisation auf die häufigeren Mikrotraumen an den unteren Extremitäten zurückzuführen ist, und dass die Ulzeration aufgrund der Kalziumablagerungen als Fremdkörper auftritt. In unserer Studie betrug das Durchschnittsalter zum Zeitpunkt der Brandverletzung 12,5 ± 8,27 Jahre und die Kalzinose entwickelte sich im Mittel nach einer Zeitspanne von 37,5 ± 14,95 Jahren (das Durchschnittsalter bei Beginn war 50,5 ± 14,53 Jahre). Es gab keinen signifikanten Unterschied zwischen Brandnarben, die mittels Hauttransplantation behandelt wurden, und solchen, bei denen keine Hauttransplantation durchgeführt wurde. Die Ulzera verheilten nach Resektion oder Extraktion der Ablagerungen ohne Rezidiv an derselben Stelle. Im Gegensatz zu früher gemeldeten Fällen beobachteten wir zwei Fälle einer spät einsetzenden Kalzinose ohne Ulzeration bei Brandnarben an den oberen Extremitäten.