Pachydermoperiostosis (PDP)

At a glance

Characterized by hypertrophic osteoarthropathy, digital clubbing, and subperiosteal new bone formation leading to pain, cutis verticis gyrata, seborrhea, and hyperhidrosis.

Synonyms

Primary Hypertrophic Osteoarthropathy; Idiopathic Hypertrophic Osteoarthropathy; Touraine-Solente-Gole Syndrome; Friedreich-Erb-Arnold Syndrome.

History

First described by Nikolaus Friedreich, a German pathologist and neurologist, in 1868.

Incidence

Pachydermoperiostosis or primary hypertrophic osteoarthropathy represents 3 to 5% of all cases of hypertrophic osteoarthropathy. The male-to-female case ratio is approximately 7:1. It is more common in African Americans than whites. It is a rare disorder in the United States and the precise incidence is unknown. Between 200 and 300 cases have been reported overall.

Genetic inheritance

Autosomal dominant pattern with variable penetrance; autosomal recessive forms have been reported.

Pathophysiology

Homozygous mutations of the 15-hydroxyprostaglandin dehydrogenase gene (HPGD) on chromosome 4q34 or the solute carrier organic anion transporter family member 2A1 gene (SLCO2A1) on chromosome 3q22.1-2 lead to a failure of PGE₂ degradation. Elevated PGE₂ results in overexpression of vascular endothelial growth factor (VGEF) with subsequent osteoblast stimulation and excessive bone formation.

Diagnosis

Clinically patients affected with this medical condition show the first appearance during childhood and the progression of the symptoms is slow. Although the evolution of the disease typically stops after 10 years, significant morbidity can be seen. Severe kyphosis, restricted motion, and neurologic manifestations are often significant. Life expectancy is normal except for individuals presenting severe mental impairment. Three forms have been described:

• Complete form with pachydermia (thickening of the facial skin and/or scalp) and periostitis;

• Incomplete form with evidence of bone abnormalities but lacking pachydermia;

• Form fruste with prominent pachydermia and minimal to absent skeletal changes.

Clinical aspects

Features include skin anomalies (thick skin, hypoplastic hyperconvex fingernails, cutis gyrata, hyperhidrosis) and limb malformations (epiphyseal and cortical anomalies, terminal broadening fingers, arthrosis). Lordosis, dislocated hip, genu varum, osteolysis, and osteoporosis may occur. Acromegaloid facial features have been described.

Precautions before anesthesia

Evaluate the airway in case of severe pachydermic and acromegaloid changes (clinical, radiographs). The thyroid gland should be checked.

Anesthetic considerations

There is no case description relating to anesthesia. Direct laryngoscopy and tracheal intubation can be difficult and might require adapted anesthetic management. Digital pulse oximetry sensors can be of poor reliability because of fingernail deformations. Careful intraoperative positioning is needed because of skeletal involvement. Vascular access can be difficult because of skin thickening.

Pharmacological implications

Avoid muscle relaxants until tracheal intubation is achieved and lung ventilation is confirmed.