A 44‐year‐old man who had worked as a plumber and was currently working as a bricklayer was referred to our hospital because of a 2‐year history of progressive dyspnea. Physical examination revealed cyanosis, clubbing of the fingers, and edema of the inferior extremities. Chest auscultation revealed bilateral inspiratory crackles predominantly at the lung bases. Remarkably, there were several painful, firm papules and nodular lesions over the fingertips of the hands, some with whitish crusts (Fig. 1). These lesions had appeared 2 years before and gradually increased in number and size. A full blood count was normal apart from moderate erythrocytosis and lymphopenia. The biochemical profile (including serum levels of calcium and phosphorus and daily urinary calcium excretion) was normal. Serum angiotensin converting enzyme activity was increased at 60 U/mL (normal range, 6.1–21.1 U/mL). An antinuclear antibody test was negative. Serum complement levels were normal. Chest X‐ray film showed cardiomegaly, bilateral hilar lymphadenopathy, and interstitial infiltrates (reticulo‐nodular pattern) with a predilection for the mid and lower lung zones. A computed tomography scan of the chest confirmed mediastinal adenopathy and revealed bilateral and diffuse parenchymal abnormalities consisting of nodular opacities along the bronchovascular bundles and interlobular septa, irregular linear opacities oriented along the bronchovascular bundles, and distortion of the lobules. A gallium‐67 scan showed a “lambda” pattern created by uniform uptake in bilateral intrathoracic and right paratracheal lymphadenopathy, which is highly specific for the diagnosis of sarcoidosis.1 The recovery of bronchoalveolar lavage [TAB1][TAB]showed 61% macrophages (normal range, 80%–90%) and 35% lymphocytes (normal value, <10%). The CD4/CD8 lymphocyte ratio was increased at 3.6. Smears and cultures of the bronchial washings failed to demonstrate any infectious organisms. Cytologic examination of three sputum samples gave negative results for malignant cells, as well as for hyphae and acid‐fast bacilli. A biopsy specimen of a papular lesion of the fingertips revealed acanthosis and orthokeratotic hyperkeratosis in the epidermis. Remarkably, there were deposits of a basophilic and von Kossa‐positive material in the upper and mid dermis (Fig. 2). In some areas, there were calcific deposits perforating into the epidermis, in the manner of transepithelial elimination.2 The patient was diagnosed as having cutaneous calcinosis with transepithelial elimination associated with pulmonary sarcoidosis. Progressive pulmonary fibrosis developed despite treatment with high‐dose oral glucocorticoids. The patient died 10 months after the initiation of treatment due to severe pulmonary hypertension and right heart failure. During this period, no new cutaneous lesions appeared on the fingertips and there was a reduction in size with symptomatic improvement in some of them.

Platelets have been seen traditionally as fragments of blood mediating coagulation. However, evidence during malaria infection suggests that platelets also act against merozoites, an infectious form of malaria in the bloodstream, and megakaryocytes can release giant platelets with a larger volume than normal platelets. We propose a mathematical model to study the interaction between red blood cells, merozoites, and platelets during malaria infection. We analyzed two cases of the interaction of platelets with malaria infection. In the first one, we considered the isolated action of normal platelets and, in the second one, the joint antiparasitic action of both normal and giant platelets. Numerical simulations were performed to evaluate the stability of the equilibrium points of the system of equations. The model showed that the isolated antiparasitic action of normal platelets corroborates malaria infection control. However, the system can converge to a presence-merozoite equilibrium point, or an oscillatory behavior may appear. The joint antiparasitic action of both normal and giant platelets eliminated the oscillatory behavior and drove the dynamics to converge to lower parasitic concentration than the case of isolated action of normal platelets. Moreover, the joint antiparasitic action of platelets proved more easily capable of eliminating the infection.