Terra Firma-Forme Dermatosis, Keratotic Form

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Jennifer Elise Abdalla
Allison Cruse
Neelam Patel
Robert Brodell


terra firma, terra firma-forme, isopropyl alcohol, dermatosis, dirt-like lesion


Terra firma-forme dermatosis (TFFD) is a condition that presents as hyperpigmented patches or plaques that have a dirt-like resemblance. A keratotic form of TFFD that has not been previously reported is described in this case. The diagnosis and treatment for this condition, the alcohol swab test, did not lead to resolution of the patch in our patient. The keratotic papules had to be removed by using the edge of a microscope slide. This case report serves to provide awareness of this unique, keratotic variant that cannot be removed by wiping with isopropyl alcohol.   


1. Pablo Fernandez-Crehuet, MD, PhD. Dermoscopic signs of Duncan’s dirty dermatosis. Journal of the American Academy of Dermatology, 2016;74(5): AB50-AB50. doi:https://doi.org/10.1016/j.jaad.2016.02.199

2. Greywal T, Cohen PR. Terra firma-forme dermatosis: A report of ten individuals with Duncan’s dirty dermatosis and literature review. Dermatology Practical & Conceptual. 2015;5(3):29-33. doi:10.5826/dpc.0503a08.

3. Errichetti, E. and Stinco, G. Dermoscopy in terra firma‐forme dermatosis and dermatosis neglecta. Int J Dermatol, 2017;56:1481-1483. doi:10.1111/ijd.13686

4. Fernández-Crehuet P, Ruiz-Villaverde R. Terra firma–forme dermatosis. CMAJ: Canadian Medical Association Journal. 2016;188(4):285. doi:10.1503/cmaj.150075.

5. Fernández-Crehuet P, Ruiz-Villaverde R. Dirt-Like Hyperpigmented Plaques on the Dorsal Aspect of Both Feet. Journal of Clinical & Experimental Dermatology Research. 2015; 6(1). doi:10.4172/2155-9554.1000257