Inclusion Criteria

Concurrent Medication:

Allowed:

• Anti-HIV therapy provided therapy has remained constant in the 4 weeks prior to study entry.
• Narcotic analgesia after the first week of treatment ONLY IF the patient is not experiencing somnolence.

Patients must have:

• Documented HIV infection or AIDS.
• Biopsy-confirmed aphthous ulceration of the mouth or esophagus lasting at least 2 weeks.
• Negative culture of ulcer for Herpes simplex.
• En face diameter of >= 5 mm for largest aphthous ulcer.
• Life expectancy of at least 3 months.

NOTE:

• This study is approved for prisoner participation.

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

• Known allergy to thalidomide.
• Grade 2 or worse bilateral peripheral neuropathy.

EXCLUDED FOR MAINTENANCE PHASE:

• Toxicity other than somnolence in acute phase that required discontinuation of drug.

Concurrent Medication:

Excluded:

• Acute therapy for opportunistic infection.
• ddC.
• Pentoxifylline.
• Methotrexate, trimetrexate, antineoplastic alkylating agents.
• Other putative immunomodulators.
• CNS depressants and/or medications with sedative or hypnotic effect.
• Systemic and/or oral topical corticosteroids.
• Systemic chemotherapy for Kaposi's sarcoma or other malignancies.
• Compounded antibacterial mouthwashes containing anti-infective agents (such as doxycycline, minocycline, tetracycline, or nystatin).

Concurrent Treatment:

Excluded:

• Radiation to head and/or neck.

Patients with the following prior conditions are excluded:

• History of grade 2 or worse bilateral peripheral neuropathy.
• Change in anti-HIV therapy within 4 weeks prior to study entry.
• Prior enrollment in ACTG 251 or prior treatment of aphthous ulcers with thalidomide.

Prior Medication:

Excluded:

• Systemic and/or oral topical corticosteroids within 1 week prior to first set of bloods drawn.
• Other putative immunomodulators within 2 weeks prior to study entry.
• Prior thalidomide for aphthous ulcers.