eMedicine Specialties > Dermatology > Reactive & Inflammatory Dermatoses
Lichen Spinulosus
Updated: Oct 30, 2009
Introduction
Background
Lichen spinulosus is an uncommon dermatosis manifested by large patches of follicular papules topped by keratotic spines (see Media Files 1-2). In 1883, Crocker published a description of lichen spinulosus. Since then, few other similar reports were published until 1990, when Friedman presented data on 35 patients with lichen spinulosus.1 The etiology is unknown. Some minor progress has been made in therapy for lichen spinulosus.
Lichen spinulosus on the abdomen.
Close-up view.
Pathophysiology
The classic lesion of lichen spinulosus is a keratotic plug located within the dilated follicular orifice. Histologically, an inflammatory lymphohistiocytic infiltrate occurs around the follicle and in the dermis. Hyperkeratosis, parakeratosis, and acanthosis are visible in the follicle. Differentiating lichen spinulosus from keratosis pilaris by microscopy may not be possible.
In the past, lichen spinulosus was reported to be associated with the administration of arsphenamine, thallium, gold, and diphtheria toxin. More recently, authors have noted association with HIV disease2 and Crohn disease.3 These associations may reflect the interests of the authors. Kabashima et al reported lichen spinulosus in an alcoholic patient.4
Frequency
United States
Apparently, lichen spinulosus is not a common disorder. This conclusion is based on the paucity of published reports regarding lichen spinulosus.
International
Lichen spinulosus has been reported worldwide. In 1990, Friedman described 35 patients with lichen spinulosus. He and his coworkers in the Philippines examined 7435 people attending a dermatology clinic.1 The incidence of lichen spinulosus was approximately 5 cases per 1000 population with skin disorders. This prevalence exceeds reports from various American surveys on cutaneous diseases in children and adolescents.
Mortality/Morbidity
Lichen spinulosus affects only the skin and is not known to be associated with abnormalities of internal organ systems. Occasionally, a patient with lichen spinulosus reports pruritus. Otherwise, the disorder mostly is of cosmetic significance. Misdiagnosis can result in inappropriate treatment.
Race
Worldwide distribution suggests no predilection of lichen spinulosus in any ethnic group.
Sex
Case reports suggest an equal distribution of lichen spinulosus in males and females. Friedman's study in the Philippines included 14 males and 21 females.
Age
Reports indicate that lichen spinulosus is a disease that occurs during childhood to young adulthood. Peak incidence appears to occur during adolescence. Lichen spinulosus can persist for decades. In most patients, lichen spinulosus remits spontaneously within 1-2 years. Friedman calculated that in the Philippines, the average age at onset was 16.2 years ± 10.1 years.
Clinical
History
Lichen spinulosus tends to have a sudden onset and is not accompanied by other signs or symptoms. The keratotic papules group into large plaques that can spread rapidly to affect large areas of skin.
Physical
- Patches and plaques of follicular papules have a diameter that ranges from 2-5 cm.
- Patches are distributed symmetrically over the integument.
- Patches affect the neck, buttocks, abdomen, trochanters, knees, and extensor surfaces of the arms.
- Individual papules are flat to conical.
- Individual papules usually are small, approximately 1-3 mm in diameter.
- Papules have a pointed or hairlike horny spine that extends approximately 1 mm around the tip of the follicle.
- When a patch is rubbed gently with the fingers, it feels similar to a nutmeg grater.
Causes
The cause of lichen spinulosus is unknown. Infection has been postulated, but no data support this hypothesis. Other authors have suggested that lichen spinulosus is part of atopy, but no association of lichen spinulosus with atopy was found in the Philippines. A report notes a family with lichen spinulosus in 4 generations, an observation that suggests a genetic predisposition.
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| References |
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References
Friedman SJ. Lichen spinulosus. Clinicopathologic review of thirty-five cases. J Am Acad Dermatol. Feb 1990;22(2 Pt 1):261-4. [Medline].
Cohen SJ, Dicken CH. Generalized lichen spinulosus in an HIV-positive man. J Am Acad Dermatol. Jul 1991;25(1 Pt 1):116-8. [Medline].
Kano Y, Orihara M, Yagita A, Shiohara T. Lichen spinulosus in a patient with Crohn's disease. Int J Dermatol. Sep 1995;34(9):670-1. [Medline].
Kabashima R, Sugita K, Kabashima K, Nakamura M, Tokura Y. Lichen spinulosus in an alcoholic patient. Acta Derm Venereol. 2009;89(3):311-2. [Medline].
Tilly JJ, Drolet BA, Esterly NB. Lichenoid eruptions in children. J Am Acad Dermatol. Oct 2004;51(4):606-24. [Medline].
Cömert A, Akin O, Demirkesen C. Follicular mucinosis mimicking lichen spinulosus in an 11-year-old boy. Eur J Dermatol. Nov-Dec 2007;17(6):544-5. [Medline].
Maiocco KJ, Miller OF. Lichen spinulosus: response to therapy. Cutis. Feb 1976;17(2):294-99. [Medline].
Forman SB, Hudgins EM, Blaylock WK. Lichen spinulosus: excellent response to tretinoin gel and hydroactive adhesive applications. Arch Dermatol. Jan 2007;143(1):122-3. [Medline].
Boyd AS. Lichen spinulosus: case report and overview. Cutis. Jun 1989;43(6):557-60. [Medline].
Tilly JJ, Drolet BA, Esterly NB. Lichenoid eruptions in children. J Am Acad Dermatol. Oct 2004;51(4):606-24. [Medline].
Further Reading
Keywords
lichen spinulosus, keratosis follicularis spinulosa, lichen pilaris seu spinulosus of Crocker, keratosis follicularis spinosa of Unna
