Amoxicillin Rash in Infectious Mononucleosis
A 7-year-old girl presented to the emergency department with an itchy rash. Eight days before presentation, she had been seen by her pediatrician for pharyngitis and received treatment with amoxicillin. At the current visit, her temperature was 39.8°C. Physical examination revealed generalized erythematous papules and macules involving her face (Panel A), her trunk (Panel B), and her arms and legs, sparing her palms and the soles of her feet. The tonsils were purulent, and the anterior and posterior cervical lymph nodes were enlarged. Laboratory studies showed a white-cell count of 8700 per cubic millimeter (reference range, 4000 to 11,500), with 66% lymphocytes (reference range, 20 to 40). A mononuclear spot test was positive. A diagnosis of amoxicillin rash in infectious mononucleosis was made. Patients who receive amoxicillin for the treatment of infectious mononucleosis consequent to infection with Epstein–Barr virus may be subject to the development of a morbilliform rash. However, this rash may not be predictive of a true allergy to penicillins. The patient’s parents were advised to stop the amoxicillin, and the patient’s rash resolved completely within 3 weeks.
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.