Skin nodules can arise from a variety of underlying causes, ranging from relatively harmless conditions to more serious medical issues. They are essentially small lumps that can appear on or just under the skin's surface.
Common Causes of Skin Nodules
Many factors can contribute to the development of skin nodules, including:
- Infections: Bacterial (e.g., boils, abscesses), fungal (e.g., sporotrichosis), or viral infections can trigger nodule formation.
- Inflammation: Inflammatory conditions, such as rheumatoid nodules associated with rheumatoid arthritis, can lead to the development of nodules.
- Cysts: Epidermoid cysts and other types of cysts can sometimes feel like nodules under the skin.
- Skin Growths: Benign growths like lipomas (fatty tumors) or dermatofibromas can present as nodules.
- Trauma or Injury: Physical injury can sometimes lead to the formation of nodules as the body heals.
- Foreign Bodies: Splinters or other foreign objects embedded under the skin can cause an inflammatory reaction and nodule formation.
- Autoimmune Diseases: Conditions like granuloma annulare, sometimes linked to autoimmune issues, can present with nodules.
- Sun Exposure: Prolonged sun exposure can increase the risk of certain skin cancers, which may manifest as nodules.
- Friction: Chronic friction or irritation can lead to the development of nodules.
- Skin Cancer: In some instances, skin cancer (basal cell carcinoma, squamous cell carcinoma, melanoma) can present as a nodule.
Examples of Conditions That Cause Skin Nodules
| Condition | Description |
|---|---|
| Boils/Abscesses | Bacterial infections of hair follicles or skin that lead to painful, pus-filled nodules. |
| Lipomas | Benign fatty tumors that feel like soft, movable nodules under the skin. |
| Rheumatoid Nodules | Firm nodules that develop under the skin in people with rheumatoid arthritis, often near joints. |
| Epidermoid Cysts | Small, usually painless cysts filled with keratin, often appearing as nodules. |
| Dermatofibromas | Benign skin growths that are firm and often slightly raised, sometimes appearing after minor trauma. |
| Granuloma Annulare | A chronic skin condition that presents as raised, reddish or skin-colored nodules arranged in a ring-like pattern. |
| Skin Cancers | Certain skin cancers can initially appear as nodules that may grow over time. It is important to see a dermatologist for any new or changing skin nodules. |
When to See a Doctor
It's important to consult a doctor if you notice any new or changing skin nodules, especially if they are:
- Painful or tender
- Growing rapidly
- Bleeding or oozing
- Accompanied by other symptoms like fever or fatigue
A healthcare professional can properly diagnose the cause of the nodule and recommend the appropriate treatment.
