Pachydermoperiostosis: A rare case study

Introduction: Pachydermoperiostosis (PDP), first described in 1868, is a rare hereditary disorder characterised by periostosis, clubbing and pachydermia. Prior to 1990, only 96 cases had been described in literature1.
Case Study: A 45-year-old obese female presented complaining of atrophic scaly erythematous plaques on the extensor surfaces of her elbow since her early 20’s. On examination, she was observed to have finger and toe clubbing, facial and scalp seborrheic dermatitis, mild acne, flushing, palmoplantar hyperhydrosis and very poor dentition. She also complained of multiple joint pains, which over the years had various diagnoses including rheumatoid arthritis and psoriatic arthritis. Her extensive past medical history included gastric ulcers and metabolic syndrome.
Discussion: PDP is known to more commonly occur in men, with a 9:1 predominance. It is believed to be inherited in an autosomal dominant pattern, with incomplete/variable penetrance. Three forms of PDP are described: (1) complete or classic form with dermal and skeletal changes, (2) an incomplete form with evidence of skeletal changes but no dermal changes, and (3) a forme fruste form with prominent dermal changes but minimal-to-absent skeletal changes. Diagnosis is based on clinical features, and/or radiological evidence of subperiosteal bony changes1.
Conclusion: PDP is rare but presents with the distinct clinic-radiologic features. Early diagnosis helps in reducing the morbidity and in prognostication.
1. Rastogi R, Suma G, Prakash R, Rastogi UC, Bhargava S, Rastogi V. Pachydermoperiostosis or primary hypertrophic osteoarthropathy: A rare clinicoradiologic case. The Indian Journal of Radiology & Imaging. 2009;19(2):123-126. doi:10.4103/0971-3026.50829.

Dr. Emily Shao