April Fools' 2016: Cactus disease (paleo-induced mineral periostitis)

Case contributed by Matt Skalski
Diagnosis certain


Hand pain with areas of skin elevation. History of strict paleo diet for last 18 months.

Patient Data

Age: 30 years
Gender: Male

This case is fictitious and the described condition is not a real diagnosis. The images in this case have been digitally altered. The case was originally published as one of Radiopaedia.org's April Fools' cases

Numerous perpendicular periosteal projections from the phalanges, metacarpals, carpals, and visualized distal radius and ulna, with overlying skin tenting. This appearance is pathognomonic of cactus disease.

Photograph 1: Cactus disease with multiple areas of skin tenting, a sign only seen in severe disease. Photograph 2 & 3: Hands at the Cuevas de las Manos, Argentina estimated to be 12,000 years old. Several silhouettes demonstrate features of cactus disease supporting its Paleolithic origins. 

Case Discussion

Paleo-induced mineral periostitis (PiMP) is a recently recognized disease attributed to the so-called “paleo diet”. It most frequently involves the metacarpals and phalanges producing perpendicular periosteal projections (“spines”), an appearance that has lead to the alternative name of “cactus disease”. In severe cases the spines can tent the skin and present clinically, although the majority of cases are only detected radiographically after patients complain of hand pain, particularly when squeezing fruits (e.g. crushing goji berries).

Proponents of the paleo diet continue to deny that it causes PiMP, however a strong temporal association and correlation between length of diet and disease severity have proved scientifically robust; 2016 Cochrane Library metareview. Supportive archeological evidence from paleolithic human populations also exists including cave paintings in Argentina showing cactus hands 12,000 years ago (pictured above).

The European Society for Hand Models recently listed the paleo diet as a category 5 risk (alongside wood work, wicket keeping and thumb wrestling) after founding member Spike E. Hanzenfeat announced that his once "really really, ridiculously good looking hands" had been "internally shashlicked" within seven months of commencing the diet. A Broadway adaptation of his story entitled "The Stuff Fools Swallow" is expected in late 2017.

Know Your Risk
Individuals concerned about their dietary risk for cactus disease are advised to complete the PiMP online screening tool.

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.