Sarcoidosis is a systemic disease of unknown etiology with multi-system affection. It typically involves the skin, eyes, hilar lymph nodes, and pulmonary parenchyma. However, as any organ system could be involved, one has to be aware of its atypical manifestations. We present three uncommon manifestations of the disease. Our first case presented with fever, arthralgias, and right hilar lymphadenopathy with a history of tuberculosis in the past. He was treated for tuberculosis but had a relapse of symptoms three months after completion of treatment. The second patient presented with a headache for two months. On evaluation, cerebrospinal fluid examination showed evidence of aseptic meningitis, while an MRI of the brain demonstrated enhancement of the basal meninges. The third patient was admitted with a mass on the left side of the neck for one year. On evaluation, he was found to have left cervical lymphadenopathy, with its biopsy showing non-caseating epitheloid granuloma. Immunofluorescence did not show evidence of leukemia or lymphoma. All the patients had negative tuberculin skin tests and elevated serum angiotensinconverting enzyme levels supporting the diagnosis of sarcoidosis. They were treated with steroids with complete resolution of symptoms and no recurrence at follow-up. Sarcoidosis is an underdiagnosed entity in India. Thus, awareness of the atypical clinical features could lead to early recognition of the disease and its treatment.

Dapsone is used in the treatment of a variety of dermatological conditions and prophylaxis of opportunistic infections. However, if consumed at a dose of more than 200 mg/day, it can cause methemoglobinemia, a condition characterized by elevated methemoglobin levels in the blood; methemoglobin is an abnormal form of hemoglobin, containing iron in the ferric state (Fe 3+ ) rather than the reduced ferrous form (Fe 2+ ) found in hemoglobin. A small amount of it is produced in the body due to oxidant damage to the red blood cells. Methemoglobinemia can cause varied clinical manifestations involving the cardio-respiratory and nervous systems depending upon the level of methemoglobin. While it could be congenital, it is commonly caused by exposure to drugs that cause oxidation of hemoglobin, such as benzocaine, dapsone, and nitrates. We report a case of dapsone-induced methemoglobinemia in a previously healthy young female who had consumed 15 tablets of dapsone 100 mg with suicidal intent. She presented with central cyanosis, breathlessness, and altered sensorium after five days of consumption. While the pulse-oximeter showed oxygen saturation (SaO 2 ) of 84%, arterial blood gas (ABG) analysis showed partial pressure of oxygen (PaO 2 ) of 427 mmHg and SaO 2 of 98%. This "saturation gap" occurred due to the presence of the abnormal hemoglobin variant. Her cyanosis did not improve despite giving 100% supplemental oxygen. There was no cardiac or respiratory cause to account for her cyanosis. Her methemoglobin level was 45.8%. She was successfully treated with specific antidote methylene blue, mechanical ventilation, and other symptomatic measures. The purpose of this presentation is to help clinicians recognize this condition early, because, if left untreated, it might prove fatal. The diagnostic clues include refractory hypoxemia, central cyanosis in the absence of cardiac and respiratory causes, saturation gap, and chocolate-colored blood.

Pulmonary arterial hypertension (PAH) is an uncommon manifestation of systemic lupus erythematosus (SLE), affecting about 0.5% to 23.3% of the population worldwide. The causes of PAH associated with SLE are multifactorial. While it is generally associated with a full-blown picture of SLE, it may rarely be the presenting manifestation of the disease. We describe the case of a middle-aged woman who presented with features of severe PAH due to SLE. She was treated with vasodilators and immunosuppression (steroids and mycophenolate mofetil), with a partial response to treatment at six months follow-up.

Scrub typhus is a common cause of an acute, unexplained febrile illness. Without proper treatment, it can lead to life-threatening complications and even death. We present the case of a 16-year-old girl who presented with complaints of fever with reddish spots all over her body for 10 days and breathing difficulty for three days. She had an episode of gum bleeding just prior to admission and two episodes of hemoptysis after admission. She had severe thrombocytopenia, a low serum fibrinogen level, raised D-dimer levels, a raised activated partial thromboplastin time as well as a raised prothrombin time, and an international normalized ratio. Her chest radiograph showed diffuse bilateral interstitial infiltrates. A diagnosis of disseminated intravascular coagulation and diffuse alveolar hemorrhage secondary to possible hematological malignancy or vector-borne infectious disease was made. She was treated with intravenous doxycycline and broad-spectrum antibiotics, along with other supportive measures. Bone marrow aspiration and biopsy showed normal trilineage differentiation, normal erythropoiesis, myelopoiesis, and megakaryopoiesis. Finally, a positive immunoglobulin M (IgM) antibody for scrub typhus clinched the diagnosis. Her condition improved over the next week, and she was discharged with the advice to continue oral doxycycline for a week. This case highlights one of the rare complications of scrub typhus, disseminated intravascular coagulation, and the importance of timely initiation of treatment in such patients.