Lymphadenopathy

Lymphadenopathy refers to lymph node enlargement. Lymph nodes are considered enlarged when the diameter exceeds 1cm for cervical or axillary nodes and 1.5 cm for inguinal nodes.

Lymphadenopathy is due to proliferation of normal lymphoid elements or to infiltration by malignant or phagocytic cells. 

The common causes of generalized lymphadenopathy are:
1. Infections: bacterial, fungal, viral
2. Autoimmune disorders: rheumatoid arthritis, lupus erythematosus,  dermatomyositis, 

3. Malignancies: hodgkins disease, non hodgkins lymphoma, leukemia, histiocytic disorders
4. Lipid storage disease: Gauchers disease, Niemann Pick disorders
5. Drig reactions
6. Others: serum sickness, sarcoidosis

The following are the drainage areas of Regional nodes. Meaning any infections or problems on involved areas will have the lymph node which will enlarge:
1. Abdominal and pelvic: lower extremity, abdomen and pelvic organ
2. Axillary: hand, arm, chest wall, upper and lateral abdominal wall, breast
3. Cervical: tongue, external ear, parotid, superficial tissues of the head and neck,  larynx, trachea and thyroid
4: epitrochlear: hand and forearm
5. Iliac: lower abdomen, part of the genitalia, urethra and bladder
6. Inguinal: scrotum and penis in males, vulva and vagina in females, skin of the lower abdomen, perinuem, gluteal region
7. Mediastinal: thoracic viscera
8. Occipital: posterior scalp, 

9.. Popliteal: knee joint, skin of the lateral lower leg and foot
10. Preauricular: eyelid, conjunctiva, cheeks, temporal scalp
11. Submaxillary submental: teeth, gums, tongue, buccal mucosa
12. Supraclavicular: head, neck, arms, superficial thorax, lungs, mediastinum, abdomen

So, guided by history and physical examination, the physician would know how to manage patients with lymphadenopathy. Though, most patients have viral
Infections and need no treatment, there are some who need antibiotic and surgical interventions.