Protothecosis is a disease found in
humans caused by a type of mutant
green algae that lacks chlorophyll. The two most common species are
Prototheca wickerhami and Prototheca zopfii. Prototheca is found
worldwide in sewage. Infection is rare despite high exposure, and can be
related to a defective immune system.
The two main forms of protothecosis are cutaneous and disseminated. Cats are
exclusively infected with the cutaneous, or skin, form. Symptoms include soft
lumps on the skin of the ears, legs, feet, nose, and head. Infection usually
occurs through a wound in the skin. The disseminated form is seen in dogs and
humans. The algae enters the body through the mouth or nose and causes infection
in the intestines. From there it can spread to the eye, brain, and kidneys.
Symptoms can include diarrhea, weight loss, weakness, inflammation of the eye (uveitis),
retinal detachment, deafness, and seizures.
Diagnosis is through
culture or finding the organism in a biopsy. Surgery is the treatment of choice
for the cutaneous form. Treatment of the disseminated form is very difficult,
although use of antifungal medication has been successful in a few cases.
for cutaneous protothecosis is guarded and depends on the surgical options.
Prognosis for the disseminated form is grave.
Ettinger, Stephen J.;Feldman, Edward C.(1995).Textbook of Veterinary
Internal Medicine(4th ed.). W.B. Saunders Company.