[Hydroxychloroquine-not always a harmless drug for off label use in dermatology]. / Hydroxychloroquin ­ nicht immer ein harmloses Medikament für den Off-label-Gebrauch in der Dermatologie.

Hydroxychloroquine is used for treatment of inflammatory diseases. It is considered to have few adverse effects. We report on a woman who developed a severe skin rash after intake of hydroxychloroquine, which she received for treatment of her lichen planopilaris. Based on the clinical, laboratory and histological findings the diagnosis of a drug reaction with eosinophilia and systemic symptoms (DRESS)-like drug reaction was established. Our case illustrates that hydroxychloroquine can lead to severe adverse effects in rare cases and that patients receiving this drug must be thoroughly informed.

Cutaneous tissue samples show significant shrinkage during histopathological work-up: a real-world study.

BACKGROUND: Excision and histological examination of cutaneous neoplasms are very common diagnostic and therapeutic procedures in dermatological practice. There are often discrepancies between tissue seize in vivo and after histopathological work-up. This may raise questions according to tumor sizes or safety margins. METHODS: To investigate the effect of excision and histological processing on the properties of cutaneous neoplasms in real-life 401 specimens in 324 patients were prospectively investigated. Delineated excision margins of cutaneous neoplasms were documented prior to (T0) and post excision (T1). Length, width and thickness were measured after ≥48 h of formalin fixation (T2) and after sectioning (T3) on final histological slices. Accompanying parameters such as patient age, gender, anatomical site, and tumor entity were evaluated. RESULTS: All post-processed tissue exhibited a significant (P<0.001) median (interquartile range) reduction in length, width and thickness of 21.0% (9.5-30.0), 30.7% (20.0-40.0), and 28.0% (4.8-46.7), respectively, irrespective of site, patient age or tumor entity. Maximum median (IQR) reduction for the length and the width was observed right after excision (17.0% [4.3-25.0] and 14.0% [11.1-28.6] reduction). No significant median (IQR) tissue changes between T1 and T2 were observed (length: 4.8% (-4.3-13.3); width: 0% (-17.6-11.1); thickness 0% (-32.0-20.0). Subgroup analyses showed significantly greater tissue shrinkage in younger patients and for tissue sample sites (trunk or lower extremities). CONCLUSIONS: Most relevant shrinkage of cutaneous samples occurs right after excision. Age- and site-depended tissue contractility can influence these effects. Formalin fixation does not affect tissue shrinkage. Smaller tissue sizes on histopathological reports are to be expected.