Methylene blue is a chromophore dye known for its photosensitizing properties. It is also administered intravenously as a tracer in parathyroid surgery to identify abnormal glands. We describe 2 cases of acute methylene blue-induced phototoxicity in patients who underwent parathyroidectomy. Both patients developed an acute vesiculopustular inflammatory rash on the anterior neck corresponding to the site exposed intraoperatively to overhanging surgical lights. One of the patients also developed a bulla on her finger at the site of attachment of the oxygen probe. Biopsies were taken from both patients at different time points. The histological findings included destruction of sebaceous glands and deposition of diastase-periodic acid-Schiff-positive hyaline material around dermal blood vessels. These features are similar to those seen in skin treated with photodynamic therapy and systemic photosensitivity disorders such as the porphyrias. The wavelengths of light emitted by the surgical lights and oxygen probe overlap with the absorption spectrum of methylene blue. This resulted in excitation of the systemically administered methylene blue at exposed sites, with resultant local tissue damage and a phototoxic reaction.

No abstract

We present the case of a 10-year-old boy who was admitted with 3 months of episodic febrile neutropenia and a new petechial rash. Routine bloods identified neutropenia, thrombocytopenia, and a raised alanine aminotransferase. The dermatology team was consulted in light of the symmetrical petechial eruption of the upper torso. A punch biopsy of the lesion was consistent with early capillaritis. The results showed superficial dermal red blood cell extravasation with mild perivascular lymphohistiocytic inflammatory infiltrate. There was no evidence of an atypical lymphoid infiltrate in the skin biopsy. An initial bone marrow aspirate showed an abnormal mature T-cell population consisting of CD4 and CD8 T cells with gamma-delta positivity. Karyotyping was also done, which demonstrated isochromosome 7q. These findings were consistent with a diagnosis of hepatosplenic T-cell lymphoma (HSTL). The patient underwent fourth-line chemotherapy due to refractory relapsing disease but sadly passed away within 12 months of diagnosis. HSTL is a rare and aggressive subset of peripheral T-cell lymphoma. Prognosis is poor with a median survival of < 1 year from diagnosis. However, reports suggest improved outcomes if intensive, early, highdose chemotherapy is used alongside hematopoietic stem cell transplantation. Therefore, there is an impetus to attain early diagnosis for aggressive early treatment and improved patient outcomes. Capillaritis, presenting as asymptomatic nonpalpable purpura, can be a rare presenting feature of HSTL. Dermatologists could play a pivotal role in the early recognition of this rare but aggressive hematological malignancy and promote prompt treatment resulting in better patient outcomes.