You are in: eMedicine Specialties > Dermatology > DISEASES OF THE ADNEXA Perforating FolliculitisArticle Last Updated: May 17, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: James W Patterson, MD, Director of Dermatopathology, Professor of Pathology and Dermatology, Departments of Pathology and Dermatology, University of Virginia Medical Center James W Patterson is a member of the following medical societies: American Academy of Dermatology, American College of Physicians, American Medical Association, American Society of Dermatopathology, Medical Society of Virginia, Royal Society of Medicine, Society for Investigative Dermatology, and United States and Canadian Academy of Pathology Editors: Timothy McCalmont, MD, Director, UCSF Dermatopathology Service, Professor of Clinical Pathology and Dermatology, Departments of Pathology and Dermatology, University of California at San Francisco; Michael J Wells, MD, Associate Professor, Department of Dermatology, Texas Tech University Health Sciences Center; Rosalie Elenitsas, MD, Associate Professor of Dermatology, University of Pennsylvania School of Medicine; Director, Penn Cutaneous Pathology Services, Department of Dermatology, University of Pennsylvania Health System; Joel M Gelfand, MD, MSCE, Medical Director, Clinical Studies Unit, Assistant Professor, Department of Dermatology, Associate Scholar, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania; Dirk M Elston, MD, Director, Department of Dermatology, Geisinger Medical Center Author and Editor Disclosure Synonyms and related keywords: acquired perforating dermatosis, acquired perforating dermatitis, Kyrle disease, Kyrle's disease, hyperkeratosis follicularis et parafollicularis in cutem penetrans, perforating disorder of renal failure, elastosis perforans serpiginosa INTRODUCTIONSection 2 of 10
  BackgroundIn classic perforating folliculitis, keratotic follicular papules develop, particularly over extensor surfaces. Microscopically, the disorder is characterized by disruption of the infundibular portion of the follicular wall, with transepidermal (transfollicular) elimination of connective tissue elements and cellular debris. The condition may present as an isolated finding, apparently unrelated to other disease states, but also can be associated with chronic renal failure. Perforating folliculitis is closely related, if not identical, to the acquired perforating dermatosis that occurs with chronic renal disease. Kyrle disease (hyperkeratosis follicularis et parafollicularis in cutem penetrans) probably simply represents an exaggerated form of perforating folliculitis. In addition, another disorder of transepidermal elimination, elastosis perforans serpiginosa, occasionally displays involvement of follicular units. PathophysiologyAs in Kyrle disease, the concept of an extrinsic keratin plug penetrating the epidermis generally has been discredited. Abnormally premature keratinization at the expense of proliferation is a possible explanation, as proposed by Carter and Constantine and Tappeiner et al in Kyrle disease. A role for fibronectin has been postulated. In addition, a primary alteration of connective tissue or deposition of foreign material within the superficial dermis, with subsequent engulfment and elimination by proliferative follicular epithelium, also is conceivable as a mechanism. Such a response to experimental implantation of foreign material has been described. In addition, evidence suggests a pathologic role for excessively coiled hairs. Mehregan first proposed that curled hairs within follicular canals may act as springs, penetrating the lateral follicular wall, thereby initiating the process of transepidermal elimination. Support for this concept has been provided by an ultrastructural study of acquired perforating dermatosis that showed hair shaft fragments within transepidermal channels, even in patients in whom follicular involvement was not demonstrable on routine light microscopy. Factors that may promote coiling of hairs include follicular hyperkeratosis (occasional perforated follicles can be identified in keratosis pilaris) or contact dermatitis (eg, resulting from formaldehyde in clothing). Finally, trauma, such as scratching of pruritic skin, may well play a significant role in lesional development, possibly by setting in motion one or more of the pathologic events described above. FrequencyUnited StatesIncidence of perforating folliculitis in the United States is not known precisely, although the disorder is not uncommon. In Detroit, Michigan, 50 cases were reported during a 2-year period in the early 1970s, although this observation was followed by a declining incidence of new cases. InternationalInternational incidence is not known but probably is comparable to the incidence observed in the United States. Mortality/MorbidityMorbidity is associated with the appearance of lesions and the pruritus that occasionally accompanies them. Although cutaneous disease is insignificant, substantial morbidity or mortality rates can be seen in association with the primary underlying diseases, such as diabetes mellitus or chronic renal failure. RaceAlthough generally no ethnic predilection has been identified, 1 study found a higher incidence of Kyrle disease in chronic renal failure among African American individuals. SexPerforating folliculitis occurs equally in males and females; no sex predilection has been reported. AgeThe condition is more common in the second through fourth decades of life. CLINICALSection 3 of 10
HistoryIn perforating folliculitis, papules typically are concentrated on hair-bearing portions of the extremities and buttocks. Often, lesions are asymptomatic, although pruritus may be a striking feature, especially in patients with renal insufficiency. Lesions may wax and wane and persist for months or years. Spontaneous remission can occur, and remission following renal transplantation has been documented in 1 patient who developed lesions secondary to renal failure. PhysicalTypical primary lesions consist of scaly papules, often folliculocentric, with small central keratotic plugs and varying degrees of erythema (see Media File 1). Compression of papules may yield keratin debris and a coiled hair or hair fragments. An initial eruption of follicular pustules, followed by typical plugged papules and subsequent development of prurigo-nodularis–like lesions was reported in 1 study. The Köbner phenomenon usually is not readily demonstrable, but a linear configuration occasionally can be observed. A case of progressive generalized perforating folliculitis has been reported to be associated with erythroderma, keratoderma of the palms and soles, alopecia of the scalp and eyebrows, and nail changes. Accompanying jaundice has been observed in patients with underlying liver disease. CausesA number of reported cases appear to be idiopathic, but specific associations also have been observed. Although some associations could be coincidental, the association with chronic renal failure (including both dialysis-dependent and nondialysis patients) is relatively common, suggesting a pathogenetic link. Perforating folliculitis also is observed relatively commonly in association with diabetes mellitus. Less common associations include sclerosing cholangitis, hypertension, atherosclerotic cardiovascular disease, acanthosis nigricans, psoriasis, and phrynoderma. A single case report described an association with Poland syndrome (unilateral absence of the pectoralis major muscle and ipsilateral symbrachydactyly), but this patient also had diabetes mellitus, hyperuricemia, and dilated cardiomyopathy. DIFFERENTIALSSection 4 of 10
Acneiform Eruptions Dermatologic Manifestations of Renal Disease Elastosis Perforans Serpiginosum Folliculitis Gram-Negative Folliculitis Keratosis Pilaris Kyrle Disease Pityrosporum Folliculitis Reactive Perforating Collagenosis WORKUPSection 5 of 10
Lab Studies
Imaging Studies
Procedures
Histologic FindingsThe involved hair follicle shows focal disruption of its lateral wall, with a transepithelial channel and, often, a parakeratotic luminal plug. Connective tissue elements, including collagen and elastin, and varying numbers of inflammatory cells can be found within this transfollicular channel and within the follicular lumen, admixed with parakeratotic keratin. In some cases, a hair shaft or hair fragment can be demonstrated within the follicular lumen and/or within the transfollicular channel. The dermis surrounding the follicle typically shows sparse inflammation and focal fibrosis. TREATMENTSection 6 of 10
Medical CareSince some cases of perforating folliculitis are associated with systemic disorders (eg, diabetes mellitus, chronic renal failure), direct therapeutic efforts towards the underlying condition in these patients. Soothing antipruritic lotions may be helpful for patients in whom itching is a significant problem. UV-B irradiation also may be of general benefit in the control or amelioration of pruritus. Assessing treatments for perforating folliculitis is difficult. Although the condition is not uncommon, controlled therapeutic studies are not available. Unsuccessful treatments have included oral beta-carotene, keratolytics, antiacne therapies, and topical corticosteroids. A case reported by Zachariae and Sogaard featured progressive generalized perforating folliculitis combined with erythroderma, keratoderma, and alopecia and was resistant to corticosteroids, adrenocorticotropic hormone, psoralen plus UV-A, cytostatic agents, and aromatic retinoids. A case of phrynoderma with perforating folliculitis, reported by Neill et al, responded to 50,000 U/d of beta-carotene for 1 month, followed by 2000 U/d. Hurwitz found that a combination of antistaphylococcal therapy, phototherapy, and a topical corticosteroid lotion was helpful in controlling the condition in patients with chronic renal failure. Tretinoin 0.1% cream has cleared some lesions but has not prevented the development of others. Despite the single negative result with aromatic retinoids, these agents may play a role in the treatment of some patients with perforating folliculitis; however, experience with these agents is not sufficient to allow recommendation of a particular dosing schedule. A recent study of 5 patients showed good clinical responses with narrowband UV-B therapy. Patients were treated 2-3 times weekly. The initial dose was 400 mJ/cm2, with increases to a maximum of 1500 mJ/cm2. Lesions completely resolved after 10-15 exposures, although some recurrences were observed. Surgical CareSurgical care is not required for perforating folliculitis lesions per se, except when indicated for the performance of a diagnostic skin biopsy and subsequent wound management. Surgery in the form of renal transplantation may be an option for selected patients in whom perforating folliculitis is associated with chronic renal failure. Of course, such a procedure would be based on the overall medical needs of the patient and is not performed simply to treat the perforating folliculitis (although improvement of perforating folliculitis has been reported following renal transplantation). Consultations
FOLLOW-UPSection 7 of 10
Further Inpatient Care
Further Outpatient Care
Complications
Prognosis
Patient Education
MISCELLANEOUSSection 8 of 10
Medical/Legal Pitfalls
MULTIMEDIASection 9 of 10
REFERENCESSection 10 of 10
Perforating Folliculitis excerpt Article Last Updated: May 17, 2006 | |||||||
