Information on the following diseases can be found in the Related Disorders section of this report:

• Acromegaly
• Hypertrophic Pulmonary Osteoarthropathy

Patients with pachydermoperiostosis typically have coarse facial features with oily, thick, grooving skin on the face. Joint pain, an abnormal enlargement of the tips of the fingers and toes (clubbing), and excessive sweating of the hands and feet (hyperhidrosis) may also be present.

New fibrous bone growth (periostosis), especially of the ends of the long bones, is present in patients with pachydermoperiostosis. A condition in which the skin of the scalp has excess bulk causing depressions or grooves (cutis verticis gyrata) typically becomes apparent during the teen years.

Other symptoms found in some patients with pachydermoperiostosis may be: swelling or pain of the large joints; drooping eyelids (ptosis); a long-term inflammatory skin disease that causes dry or moist, scales and a yellowish crust (seborrheic dermatitis); disorders such as ulcers; and/or swelling of hair follicles related to large open pores of the skin.

The symptoms in patients with pachydermoperiostosis vary in severity with males typically having a more severe form of the disorder.

The cause of pachydermoperiostosis is unknown. In most cases, it is thought to be inherited as an autosomal dominant trait in which males are either more severely affected or affected more frequently than females. The disorder can also occur as a result of a spontaneous mutation (sporadic), and there have been some reports of an autosomal recessive inheritance pattern.

Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome and females have two X chromosomes. Each chromosome has a short arm designated "p" and a long arm designated "q". Chromosomes are further sub-divided into many bands that are numbered. For example, "chromosome 11p13" refers to band 13 on the short arm of chromosome 11. The numbered bands specify the location of the thousands of genes that are present on each chromosome.

Genetic diseases are determined by the combination of genes for a particular trait that are on the chromosomes received from the father and the mother.

Recessive genetic disorders occur when an individual inherits the same abnormal gene for the same trait from each parent. If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the defective gene and, therefore, have an affected child is 25% with each pregnancy. The risk to have a child who is a carrier like the parents is 50% with each pregnancy. The chance for a child to receive normal genes from both parents and be genetically normal for that particular trait is 25%. The risk is the same for males and females.

All individuals carry a few abnormal genes. Parents who are close relatives (consanguineous) have a higher chance than unrelated parents to both carry the same abnormal gene, which increases the risk to have children with a recessive genetic disorder.

Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.

Pachydermoperiostosis is a rare disorder that affects males more often than females with a ratio of 7:1. This ratio may not be totally valid since females often have milder symptoms than do men, with the fibrous bone growth (periostosis) not being detected unless X-rays are taken.

Symptoms of the following disorders can be similar to those of Pachydermoperiostosis. Comparisons may be useful for a differential diagnosis:

Acromegaly is a slowly progressive, chronic metabolic disorder in which an excess of growth hormone causes abnormal enlargement of various tissues of the body and unusual height. Most conspicuously affected are the arms, legs, jaws and face. The enlargement of soft tissue, especially of the heart, is a serious feature of this disorder. High blood pressure may be another serious consequence of Acromegaly. (For more information on this disorder choose "Acromegaly" as your search term in the Rare Disease Database.)

Hypertrophic Pulmonary Osteoarthropathy (Bamberger-Marie Disease) is a rare disorder in which there is expansion of the ends or the entire shaft of the long bones and often abnormal enlargement of the fingers and toes (clubbing). This disorder occurs in chronic pulmonary disease, heart disease and occasionally in other acute and chronic disorders.

Diagnosis
Diagnosis is made clinically. Major diagnostic criteria for HOA are clubbing of the fingers (digital clubbing) and fibrous bone growth (periostosis). Pachydermoperiostosis is the complete form of HOA. There are also three incomplete forms: clubbing alone, periostosis without clubbing, and pachyderma.

Treatment
Treatment is mostly aimed at specific symptoms. Nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids may be administered to reduce bone and joint pain associated with the disorder.

A vagotomy, a surgical procedure in which certain branches of the vagus nerve are cut, may in some instances improve joint pain and swelling. Plastic surgery may be performed to improve facial appearance.

Genetic counseling may be of benefit for patients and their families. Other treatment is symptomatic and supportive.

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com

McKusick VA, ed. Online Mendelian Inheritance In Man (OMIM). The Johns Hopkins University. Pachydermoperiostosis; PDP. Entry Number; 167100: Last Edit Date; 2/27/1996.

McKusick VA, ed. Online Mendelian Inheritance In Man (OMIM). The Johns Hopkins University. Clubbing of Digits. Entry Number; 119900: Last Edit Date; 3/18/2004.

TEXTBOOKS
Lindor NM. In: NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. Philadelphia, PA. 2003:129-30.

Fauci AS, Braunwald E, Isselbacher KJ, et al., eds. Harrison’s Principles of Internal Medicine. 14th ed.McGraw-Hill Companies. New York, NY; 1998.

Champion RH, Burton JL, Ebling FJG., eds. Textbook of Dermatology. 5th ed. Blackwell Scientific Publications. London, UK; 1992:362-63.

JOURNAL ARTICLES
Pichler G, Eber E, Thalhammer G, et al. Arthralgia and digital clubbing in a child: hypertrophic osteoarthropathy with inflammatory pseudotumour of the lung. Scand J Rheumatol. 2004;33:189-91.

Seggewiss R, Hess T, Fiehn C. A family with a variant form of primary hypertrophic osteoarthropathy restricted to the lower extremities. Joint Bone Spine. 2003;70:230-33.

Levin SE, Harrisberg JR, Govendragaloo K. Familial primary hypertrophic osteo-arthropathy in association with congenital heart disease. Cardiol Young. 2002:12;304-07.

Akdeniz BG, Seekin T. Periodontal and alveolar bone abnormalities associated with pachydermoperiostosis. Periodontal Clin Investig. 2001:23;5-10.

Jajic Z, Jajic I, Nemeic T. Primary hypertrophic osteoarthropathy: Clinical, radiologic, and scintigraphic characteristics. Arch Med Res. 2001;32:136-42.

Silveira LH, Martinez-Lavin M, Pineda C, et al. Vascular endothelial growth factor and hypertrophic osteoarthropathy. Clin Exp Rheumatol. 2000;18:57-62.

Jajic Z, Jajic I, Nemcic T. Hypertrophic osteoarthropathy after cerebrovascular insult. Clin Exp Rheumatol. 2000;18:262.

Demirpolat G, Sener RN, Stun EE. MR imaging of pachydermoperiostosis. J Neuroradiol. 1999;26:61-63.

Friedhofer H, Salles AG, Gemperli I, et al. Correction of eyelid anomalies in pachydermoperiostosis. Ophthal Plas Recontr Surg. 1999;15:137-38.

FROM THE INTERNET
Goyal S, Schwartz RA, Richards GM, et al. Pachydermoperiostosis. emedicine. Last updated: October 1, 2004. 12pp.
www.emedicine.com/derm/topic815.htm

Khan AN, Seriki D, Turnbull I, et al. Hypertrophic Osteoarthropathy. emedicine. Last updated: August 23, 2002. 13pp.
www.emedicine.com/radio/topic357.htm

Auger M, Stavrianeas N. Pachydermoperiostosis. Orphanet. Creation Date: April 2004. 8pp.
www.orpha.net/data/patho/GB/uk-pachydermoperiostosis.pdf