Splenomegaly
Overview The spleen is not considered a vital organ, since the body can survive without it. However, the spleen is the largest lymphoid organ and has an important role in immunity and blood filtration. Definition A spleen is considered enlarged when it can be palpated 2 cm below the costal margin or when imaging shows […]
Yaws, Bejel, and Pinta
Epidemiology and Etiology Epidemiology Yaws (most common): Bejel: Pinta: Etiology Pathogenesis Reservoir Humans are the only reservoir. Transmission Pathophysiology Clinical Presentation Yaws Primary phase: Secondary phase: Tertiary phase: Bejel Primary phase: Secondary stage: Tertiary phase: Pinta Primary phase: Secondary phase: Tertiary or late phase: Diagnosis and Management Diagnosis Because these treponemal species are morphologically indistinguishable, […]
Pneumocystis jirovecii/Pneumocystis Pneumonia (PCP)
General Characteristics Basic features of Pneumocystis Pneumocystis is a yeast-like fungus. Clinically relevant species P. jirovecii (formerly known as P. carinii) causes pneumocystis pneumonia (PCP). Epidemiology and Pathogenesis Epidemiology Reservoir The reservoir for P. jirovecii is unknown, but immunocompetent humans may play a role. Transmission P. jirovecii spreads through airborne transmission. Host risk factors Pneumocystis […]
Dermatophytes/Tinea Infections
Overview General characteristics of dermatophytes Dermatophytes are filamentous fungi that belong to the genera Trichophyton, Microsporum, and Epidermophyton. Dermatophytes have septate hyphae with chains of conidia. Classification of tinea infections Tinea infections are classified and named by the body region affected. Tinea pedis: “Athlete’s foot” Infection of the interdigital webs of the feet Tinea corporis: […]
Minimal Change Disease
Overview Definition Minimal change disease (MCD) is a primary glomerular disorder of unclear etiology that causes nephrotic syndrome. The term “minimal” refers to the minimal structural changes of the glomeruli when observed under light microscopy. Epidemiology MCD is the most common cause of nephrotic syndrome in children. Accounts for 90% of cases of nephrotic syndrome […]
Intestinal Ischemia
Overview Definition Intestinal ischemia is a decrease in blood flow to the intestines resulting in hypoperfusion that may lead to bowel infarction. Mucosal sloughing occurs after approximately 3 hours of ischemia, and necrosis occurs after approximately 6–12 hours of ischemia. Types of intestinal ischemia Epidemiology For all types, intestinal ischemia primarily affects adults > 60 […]
Constipation
Overview Definition Constipation is a symptom generally defined as bowel movements < 3 times per week; stools are frequently difficult to pass. Epidemiology Classification Constipation can be classified as either primary or secondary, as well as by duration (acute or chronic). Etiology Primary constipation Primary constipation, also known as functional constipation, is when there are […]
Hypocalcemia
Calcium Homeostasis Calcium Calcium is the most abundant mineral in the human body; 99% is found in bone. Calcium in the blood exists in 3 forms: Levels: Importance of calcium: Calcium regulation Bone, intestine, and kidneys are involved in homeostasis. Key elements of calcium regulation: Etiology Associated with ↑ PTH: Hypoparathyroidism (↓ PTH): Drug induced: […]
Chronic Myeloid Leukemia
Overview Definition Chronic myeloid leukemia is a chronic myeloproliferative neoplasm characterized by uncontrolled and dysregulated proliferation of the granulocytic lineage (mature and maturing cells), with a maintained capacity for differentiation. Chronic myeloid leukemia is also known as chronic myelocytic leukemia or chronic myelogenous leukemia. Epidemiology 20% of all leukemia in adults Incidence: In the United […]
Hypercoagulable States
Overview Definition Hypercoagulability, also referred to as a thrombophilia, refers to the increased tendency for blood to form clots, known as thrombi. Hypercoagulable states can be inherited or acquired. Epidemiology Prevalence of inherited thrombophilias: Table: Prevalence and risk of venous thromboemolism (VTE) in inherited thrombophilias Condition Prevalence Risk of VTE Factor V Leiden 3%–7% 4.3% […]