Capillaritis as a Skin Manifestation of Hepatosplenic Gamma-Delta T-Cell Lymphoma.

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, high-dose 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.

Melanin has a Small Inhibitory Effect on Cutaneous Vitamin D Synthesis: A Comparison of Extreme Phenotypes.

Epidemiology suggests that melanin inhibits cutaneous vitamin D3 synthesis by UVR. Laboratory investigations assessing the impact of melanin on vitamin D production have produced contradictory results. We determined the effect of melanin on vitamin D3 photosynthesis in healthy young volunteers (n = 102) of Fitzpatrick skin types II-VI (white to black). Participants, irrespective of skin type, were exposed to the same suberythemal UVR dose, to 85% body surface area, using solar simulated UVR or narrowband UVB (311 nm). This was repeated five times with intervals of 3-4 days between UVR exposures. Blood was taken before, during, and after the irradiation and assessed for serum 25-hydroxyvitamin D3 (25[OH]D3) as a marker of vitamin D3 status. Linear UVR dose-dependent increases in 25(OH)D3 were highly significant (P ≤ 7.7 x 10-11). The ratios of regression slopes of the different skin type groups were compared, and only skin type II was significantly steeper than the other groups. Comparisons between extreme skin types II and VI showed melanin inhibition factors of approximately 1.3-1.4, depending on the UVR source. We conclude that the inhibitory effect of melanin on vitamin D3 synthesis is small, compared with erythema, but that this difference may be sufficient to explain the epidemiological data.

Spontaneous painful subungual thumb haematoma.

We present the case of a 56-year-old man who presented to our accident and emergency department 15 years after a work-based injury to his left thumb.In January 2017, the patient was woken up acutely with excruciating pain in his left thumb with no preceding trauma. On clinical examination, only a subungual haematoma was noted. Radiographs of the effected thumb demonstrated a round, lytic lesion with an accompanying hairline fracture on the distal phalanx of the left thumb. The radiologist suggested a differential diagnosis of enchondroma should be considered.The patient was referred for a routine plastic surgery outpatient appointment. Curettage sampling of the lesion was performed and a cement filler was used to prevent further pathological fractures.The biopsy report stated that the sample contained normal bone tissue with no evidence of enchondroma or other malignancy and the patient was discharged without any further complications.