Prurigo nodularis is a skin condition characterized by the formation of small, firm bumps or nodules that often cause intense itching. These nodules can appear anywhere on the body but are most commonly found on areas that are easily scratched, such as the arms, legs, and back. The condition is chronic, meaning it can persist for a long time, and the nodules may become thicker and more pronounced due to repeated scratching. The appearance of prurigo nodularis can vary depending on skin tone, with nodules ranging from pink or red to brown or even hyperpigmented. The surface of the nodules may be rough or scaly, and in some cases, they can develop a crust or scab due to scratching.

Common Visual Characteristics

The nodules associated with prurigo nodularis are typically small, measuring between a few millimeters to a centimeter in diameter. They are often dome-shaped and firm to the touch. The color of the nodules can vary based on the individual’s skin tone, appearing lighter or darker than the surrounding skin. In some cases, the nodules may cluster together, creating a patchy or scattered pattern. The surrounding skin may also show signs of irritation, such as redness or dryness, due to frequent scratching.

Areas Commonly Affected

Prurigo nodularis tends to develop on areas of the skin that are easily accessible for scratching. The most commonly affected areas include the arms, legs, back, and shoulders. However, the condition can also appear on other parts of the body, such as the abdomen or chest. In rare cases, the nodules may form on the face or scalp, though this is less common. The distribution of the nodules can vary from person to person, with some individuals experiencing a few isolated nodules and others developing numerous bumps across larger areas of the body.

Distinguishing Features

Prurigo nodularis can sometimes be confused with other skin conditions, such as eczema or insect bites. However, there are key differences that can help distinguish it. Unlike eczema, which often presents as red, inflamed patches, prurigo nodularis nodules are more defined and raised. Additionally, the intense itching associated with prurigo nodularis often leads to repeated scratching, which can cause the nodules to become thicker and more persistent over time. Insect bites, on the other hand, typically resolve on their own within a few days, whereas prurigo nodularis nodules can persist for weeks or months.

Comparison Table: Prurigo Nodularis vs. Other Skin Conditions

References

• American Academy of Dermatology
• National Institutes of Health
• Mayo Clinic