Pachydermoperiostosis

What it is

From: Orphanet

Pachydermoperiostosis (PDP) is a form of primary hypertrophic osteoarthropathy, a rare hereditary disorder, and is characterized by digital clubbing, pachydermia and subperiosteal new bone formation associated with pain, polyarthritis, cutis verticis gyrata, seborrhea and hyperhidrosis. Three forms have been described: a complete form with pachydermia and periostitis, an incomplete form with evidence of bone abnormalities but lacking pachydermia, and a forme frusta with prominent pachydermia and minimal-to-absent skeletal changes.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal cortical bone morphology · Very frequent (99-80%)

An abnormality of compact bone (also known as cortical bone), which forms the dense surface of bones.

Abnormality of epiphysis morphology · Very frequent (99-80%)

An anomaly of epiphysis, which is the expanded articular end of a long bone that developes from a secondary ossification center, and which during the period of growth is either entirely cartilaginous or is separated from the shaft by a cartilaginous disk.

Bone pain · Very frequent (99-80%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) localized to bone.

Clubbing · Very frequent (99-80%)

Broadening of the soft tissues (non-edematous swelling of soft tissues) of the digital tips in all dimensions associated with an increased longitudinal and lateral curvature of the nails.

Hyperhidrosis · Very frequent (99-80%)

Abnormal excessive perspiration (sweating) despite the lack of appropriate stimuli like hot and humid weather.

Osteomyelitis · Very frequent (99-80%)

Osteomyelitis is an inflammatory process accompanied by bone destruction and caused by an infecting microorganism.

Seborrheic dermatitis · Very frequent (99-80%)

Seborrheic dermatitis is a form of eczema which is closely related to dandruff. It causes dry or greasy peeling of the scalp, eyebrows, and face, and sometimes trunk.

Thickened skin · Very frequent (99-80%)

Laminar thickening of skin.

Abnormal fingernail morphology · Frequent (79-30%)

An abnormality of the fingernails.

Abnormal hair quantity · Frequent (79-30%)

An abnormal amount of hair.

Acne · Frequent (79-30%)

A skin condition in which there is an increase in sebum secretion by the pilosebaceous apparatus associated with open comedones (blackheads), closed comedones (whiteheads), and pustular nodules (papules, pustules, and cysts).

Arthralgia · Frequent (79-30%)

Joint pain.

Arthritis · Frequent (79-30%)

Inflammation of a joint.

Clubbing of toes · Frequent (79-30%)

Terminal broadening of the toes (distal phalanges of the toes).

Other findings in the same source

From: Orphanet

Additional reported features include Coarse facial features (Frequent (79-30%)); Cutis gyrata of scalp (Frequent (79-30%)); Decreased serum insulin-like growth factor 1 (Frequent (79-30%)); Diarrhea (Frequent (79-30%)); Edema (Frequent (79-30%)); High, narrow palate (Frequent (79-30%)); Limitation of joint mobility (Frequent (79-30%)); Long eyelashes (Frequent (79-30%)); Nausea (Frequent (79-30%)); Osteolysis (Frequent (79-30%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Childhood

Inheritance in the source

From: Orphanet

Autosomal dominant; Autosomal recessive

Frequency and the population described

From: Orphanet

Reported case(s): 204.0; Worldwide. This is a published case count, not prevalence. Point prevalence: <1 / 1 000 000; Worldwide; Class only.

Which doctor should you see?

The suggested department for discussing Pachydermoperiostosis is Orthopaedics, with a orthopaedic specialist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• What explains the change in pain, movement or function?
• Which activities need adjustment while the diagnosis is being clarified?
• What are the roles of rehabilitation, observation and surgery in this situation?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Pachydermoperiostosis. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.