Mycoplasma-Induced Rash and Mucositis
An 8-year-old girl was brought to the dermatology clinic with a 3-day history of painful lip crusting, oral ulcers, rash, and genital pain. Ten days before presentation, a fever and cough had developed. She had no history of medication use. Physical examination was notable for conjunctivitis in both eyes and ulcers in the oropharynx. There were scattered vesicular lesions across her face, and her swollen, bleeding, exudative lips made it difficult for her to open her mouth (Panel A). Targetoid lesions with vesicles were scattered across her arms and legs (Panel B, left leg), and multiple small ulcers were found in the vulvar and perianal regions. Rales were present in both lung bases. Imaging of the chest showed infiltrates in both lungs. A serum IgM antibody test and a sputum polymerase-chain-reaction test were positive for Mycoplasma pneumoniae. A diagnosis of mycoplasma-induced rash and mucositis was made. Although this postinfection mucocutaneous syndrome may manifest in a way similar to the Stevens–Johnson syndrome, the prognosis is more favorable. Supportive care was administered, and treatment with doxycycline was given for the pneumonia. Two weeks after presentation, the mucocutaneous lesions had abated, and the pneumonia symptoms resolved soon after.
Stomach
Foot X-ray AnatomyAnatomy of liverAbdominal aortic aneurysmImage of trachea blocked by chewing gum### Anatomy of the Heart: Summary The heart is a muscular organ responsible for pumping blood throughout the body, supplying oxygen and nutrients while removing waste products. It is located in the thoracic cavity, between the lungs, and is roughly the size of a fist. #### 1. **Structure:** - **Chambers:** The heart has four chambers: - **Right Atrium:** Receives deoxygenated blood from the body via the superior and inferior vena cavae. - **Right Ventricle:** Pumps deoxygenated blood to the lungs through the pulmonary arteries. - **Left Atrium:** Receives oxygenated blood from the lungs via the pulmonary veins. - **Left Ventricle:** Pumps oxygenated blood to the rest of the body through the aorta. - **Valves:** The heart contains four main valves that ensure unidirectional blood flow: - **Tricuspid Valve:** Located between the right atrium and right ventricle. - **Pulmonary Valve:** Located between the right ventricle and pulmonary arteries. - **Mitral (Bicuspid) Valve:** Located between the left atrium and left ventricle. - **Aortic Valve:** Located between the left ventricle and the aorta. #### 2. **Wall Layers:** - **Epicardium:** The outer layer, also known as the visceral pericardium. - **Myocardium:** The thick, muscular middle layer responsible for contraction. - **Endocardium:** The inner layer that lines the chambers and valves. #### 3. **Blood Supply:** - The heart receives its blood supply from the coronary arteries, which branch off the aorta. The **right coronary artery** supplies the right side of the heart, while the **left coronary artery** branches into the left anterior descending and circumflex arteries, supplying the left side. #### 4. **Electrical System:** - The heart's rhythmic contractions are controlled by its electrical conduction system, which includes: - **Sinoatrial (SA) Node:** The natural pacemaker located in the right atrium. - **Atrioventricular (AV) Node:** Receives impulses from the SA node and transmits them to the ventricles. - **Bundle of His and Purkinje Fibers:** Distribute the electrical impulse throughout the ventricles, leading to contraction. #### 5. **Function:** - The heart functions in two primary circulatory loops: - **Pulmonary Circulation:** Moves deoxygenated blood from the right side of the heart to the lungs for oxygenation. - **Systemic Circulation:** Distributes oxygenated blood from the left side of the heart to the rest of the body. The anatomy of the heart is crucial for its role in maintaining effective circulation and overall cardiovascular health. Understanding its structure helps in diagnosing and treating various heart conditions.