I found these nasty things in an old dungeon description buried in my files. The Anamab Caverns were deep in a tropical jungle and inhabited by a degenerate race of reptilian humanoids. Enjoy (well maybe not enjoy...)
From the original dungeon description: Characters staying in the complex have a base chance of 3% to be infected with a disease and a base chance of 10% to be infested with a parasite. These base chances increase by 1% per day the character stays in the complex.
Creeping Sleep - This disease is spread by insect bites or direct contact with others already infected. The victim experiences increasing tiredness for five days requiring an extra two hours sleep each day. After five days the victims continue to require additional sleep and must make a successful resistance check vs. Fair difficulty or fall into a coma-like sleep for 10 to 15 days. The victim will experience recurring bouts of sleepiness every three months until cured. The disease can be cured with a Fair test of healing during the initial five days, after which the difficulty increases to Great.
Liquid Lung - This disease is caused by an airborne fungus that growns on decaying vegetable matter. The lungs of a victim infected with this disease slowly fill with fluid, causing them to cough and choke almost continuously. Over the course of 15 days the infected victim will suffer a decline in their vitality, eventually choking to death on their own bodily fluids. Curing this disease is a Fair test of healing.
Plum Plague - This disease is spread by biting insects or surface contact with tainted surfaces. It is quick spreading and deadly. Within hours of exposure a purple blotch will appear on the skin of the victim. This blotch spreads quickly, tinting the entire body purple within four or five days. The purple patches cause extreme itching and victims are often tear at their own flesh as the disease takes hold. Curing this disease is a Good test of healing.
Nail Worms - These small creatures crawl beneath finger and toe nails and eat away at the tender flesh beneath, causing searing pain after a day's infestation. The pain is so severe that the infested limb is all but useless. Removal of these pests is a Good test of healing. Nail worms are commonly found in stagnant pools of water in warm environments.
Hair Ticks - These pests lurk on branches and low hanging vines. They exude a silky thread which dangles beneath their resting place. Any passing creature that brushes against the thread will pull the tick free and onto itself. Once on a victim the tick will find a nice patch of skin and dig in for a meal of blood. Hair ticks carry both Creeping Sleep and Plum Plague. They can be removed as an Average test of healing.