You are in: eMedicine Specialties > Dermatology > DISEASES OF THE DERMIS Kyrle DiseaseArticle Last Updated: Apr 11, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  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: Marjan Garmyn, MD, PhD, Professor, Faculty of Medicine, Katholieke Universiteit Leuven, Belgium; Chair and Adjunct Head, Department of Dermatology, University of Leuven, Belgium; David F Butler, MD, Professor of Dermatology, Texas A&M University College of Medicine; Director, Division of Dermatology, Scott and White Clinic; Director Dermatology Residency Training Program, Scott and White Clinic; Edward F Chan, MD, Clinical Assistant Professor, Department of Dermatology, University of Pennsylvania School of Medicine; Catherine Quirk, MD, Clinical Assistant Professor, Department of Dermatology, Brown University; William D James, MD, Paul R Gross Professor of Dermatology, University of Pennsylvania School of Medicine; Vice-Chair, Program Director, Department of Dermatology, University of Pennsylvania Health System Author and Editor Disclosure Synonyms and related keywords: hyperkeratosis follicularis et parafollicularis in cutem penetrans INTRODUCTIONSection 2 of 11
  BackgroundKyrle disease is characterized by the formation of large papules with central keratin plugs that may develop in a widespread distribution pattern. Histopathologically, a keratin plug mingled with necrotic cellular debris and degenerated connective tissue occupies an epidermal invagination. The disease is most closely associated with diabetes mellitus and renal failure. PathophysiologyThe concept of an extrinsic keratin plug penetrating the epidermis generally has been discredited. Carter et al have suggested that, within the epidermis, keratinization focally occurs at the expense of proliferation, with keratinization eventually occurring at the level of the basilar layer. This elicits a host inflammatory response, resulting in transepidermal elimination of keratin, cellular material, and connective tissue elements. It also is possible that the initiating step is alteration of dermal connective tissue, which then is recognized, engulfed, and eliminated by proliferative epidermis. Such a concept is supported by similar processes that occur in conditions of altered connective tissue, such as elastosis perforans serpiginosa, perforating pseudoxanthoma elasticum, and reactive perforating collagenosis. Experimental evidence has also shown that foreign particles, when located in the superficial dermis, undergo transepidermal elimination. Factors that might contribute to such a process include metabolic derangements, infection, mechanical trauma (eg, rubbing, scratching), or the springlike mechanism created by coiled-up hairs within hyperkeratotic follicular lumina. Some literature suggests that Kyrle disease may be a recessively inherited genodermatosis. FrequencyUnited StatesIn the United States and internationally, Kyrle disease is rare, except in the setting of chronic renal failure. With chronic renal failure, perforating dermatoses (that are closely related to and probably represent variants of Kyrle disease) are more common. Mortality/MorbidityMorbidity results from the appearance of the lesions and the intense itching that often is associated with the condition. However, significant morbidity and mortality may be more directly associated with the underlying disease (eg, diabetes mellitus, chronic renal failure, hepatic abnormalities). SexNo sexual predilection exists for the disease. AgeA wide age range exists among patients with Kyrle disease. The average age at time of presentation is 30 years. CLINICALSection 3 of 11
HistoryA history of an eruption of characteristic skin lesions exists, with duration ranging from 4 months to 43 years. The lesions may be asymptomatic, but tenderness and especially pruritus sometimes are reported. Without treatment, the eruption is persistent (individual lesions heal but new ones continue to develop). However, the condition has been reported to clear following therapy of the underlying systemic disease (eg, diabetes mellitus). PhysicalThe primary lesion is a small papule with silvery scale. This eventually enlarges to form a red-brown papule or nodule with a central keratin plug (Media File 1). Some, but not all, of the lesions appear to be follicular. These may coalesce to form larger keratotic plaques. Koebnerization is not ordinarily described as such, but a striking linearity of lesions sometimes is noted. The papules, nodules, and plaques of Kyrle disease tend to occur primarily on the legs, but also develop on the arms and in the head and neck region. Involvement of palms and soles is rare. Ocular changes, including keratotic lesions of conjunctiva and cornea, have been described in a single case report. CausesAs indicated above, debate about the precise pathophysiology of the disease exists. Some cases appear to be idiopathic or inherited, but other examples of Kyrle disease are associated with systemic disorders. A recent case report by Kasiakou et al noted regression of lesions following antimicrobial therapy, suggesting a role for bacterial infection in pathogenesis. The following list includes several of the associated systemic disorders:
DIFFERENTIALSSection 4 of 11
Elastosis Perforans Serpiginosum Folliculitis Hyperkeratosis Lenticularis Perstans (Flegel Disease) Keratoacanthoma Keratosis Follicularis (Darier Disease) Keratosis Pilaris Lichen Planus Perforating Folliculitis Prurigo Nodularis Reactive Perforating Collagenosis Squamous Cell Carcinoma WORKUPSection 5 of 11
Lab Studies
Histologic FindingsA partially parakeratotic plug, which fills an epidermal depression, is present. It may or may not involve a hair follicle. Marked acanthosis of surrounding epithelium usually is present. Within the plug there often is admixed basophilic debris. Keratinous material extends focally to the basilar layer and may contact the dermis. At this point, necrotic cellular material and degenerated connective tissue are noted to undergo transepidermal elimination. A surrounding mixed infiltrate usually is present, including neutrophils, lymphocytes, and epithelioid histiocytes (macrophages). TREATMENTSection 6 of 11
Medical CareKyrle disease perhaps is most important as a cutaneous sign of a systemic disorder, although idiopathic cases without systemic disease occur. Therefore, direct therapeutic efforts towards any underlying condition. For patients in whom itching is a major problem, soothing antipruritic lotions may be helpful. Consultations
MEDICATIONSection 7 of 11
Assessment of treatments for Kyrle disease is a difficult task since controlled therapeutic studies are not available for this uncommon disorder. Treatments that have been used unsuccessfully in the past include keratolytics, 5-fluorouracil, topical corticosteroids, methotrexate, mercury, chloroquine, and prednisone. A recent case showed a response to clindamycin therapy. Some improvement has been reported with vitamin A at a dose of 100,000 IU/d, with or without vitamin E at 400 IU/d. This combination has produced improvement after 1 month of therapy. Topical retinoic acid 0.1% cream also can produce improvement, and changes in lesions have been observed as rapidly as within 6-7 days. Another approach is administration of oral retinoids. In one study, isotretinoin given at a dose of 40 mg bid (1 mg/kg/day) resulted in decreased pruritus, desiccation, and slough of lesions within 4 weeks with resurfacing of skin approaching normal within 5 weeks. This drug then was decreased to 40 mg/80 mg on alternate days (0.75 mg/kg/d) for 8 more weeks and discontinued, for a total treatment course of 13 weeks. Etretinate in high doses also is effective, but relapse has been reported following discontinuation of therapy.
Drug Category: VitaminsEssential for normal DNA synthesis.
Drug Category: RetinoidsCan influence and alter abnormal keratinization.
FOLLOW-UPSection 8 of 11
Prognosis
MISCELLANEOUSSection 9 of 11
Special Concerns
MULTIMEDIASection 10 of 11
REFERENCESSection 11 of 11
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