**Core Concept:** Rheumatic fever is an inflammatory disorder that results from Group A beta-hemolytic streptococcal infections. It is a complication of streptococcal pharyngitis and has carditis, arthritis, chorea, erythema marginatum, and renal lesions as its clinical manifestations. Subcutaneous nodules are a common manifestation seen in rheumatic fever.

**Why the Correct Answer is Right:** Subcutaneous nodules are a part of the carditis associated with rheumatic fever. They are non-tender and most commonly present on extensor surfaces, such as the dorsum of the hands and feet. These nodules are caused by inflammation and accumulation of fluid and dead tissue beneath the skin, which leads to the formation of subcutaneous nodules.

**Why Each Wrong Option is Incorrect:**

A. Non-tender: Although the nodules are not tender, they are not completely painless. The correct answer is that they are "non-tender," which means less tender than tender.

B. Most common manifestation: Subcutaneous nodules are not the most common manifestation of rheumatic fever. The correct answer should be "most common manifestation," not "most common."

C. Present on extensor surfaces: While subcutaneous nodules can be found on extensor surfaces, they can also be found in other areas such as the palms, soles, and nail beds. This option is not entirely accurate.

D. Associated with arthritis: Subcutaneous nodules are not specifically associated with arthritis in rheumatic fever. While they may coexist with arthritis, they can also be seen in other conditions, making this option less specific.

**Clinical Pearl:** Subcutaneous nodules are a relatively benign manifestation of rheumatic fever that can be mistaken for malignancy or infection. They often precede other manifestations of rheumatic fever and should prompt a thorough assessment for streptococcal pharyngitis.

**Correct Answer:** D. Associated with arthritis (Rheumatic fever)

*Subcutaneous nodules are associated with rheumatic fever and can be present along with arthritis. They are a manifestation of carditis and are typically preceded by other carditis manifestations.*