Continuing Medical Education

Keratosis Circumscripta Revisited: A Case Report and Review of the Literature

LCDR Eric P. Brumwell, MC, USN; LCDR Sean J. Murphy, MC, USN

GOAL To understand keratosis circumscripta to better manage patients with the condition

OBJECTIVES Upon completion of this activity, dermatologists and general practitioners should be able to: 1. Describe the clinical presentation of keratosis circumscripta. 2. Discuss the disorders often compared to keratosis circumscripta. 3. Identify treatment options for keratosis circumscripta.

CME Test on page 378.

This article has been peer reviewed and approved Einstein College of Medicine is accredited by by Michael Fisher, MD, Professor of Medicine, the ACCME to provide continuing medical edu- Albert Einstein College of Medicine. Review date: cation for physicians. April 2007. Albert Einstein College of Medicine designates This activity has been planned and imple- this educational activity for a maximum of 1 AMA mented in accordance with the Essential Areas PRA Category 1 CreditTM. Physicians should only and Policies of the Accreditation Council for claim credit commensurate with the extent of their Continuing Medical Education through the participation in the activity. joint sponsorship of Albert Einstein College of This activity has been planned and produced in Medicine and Quadrant HealthCom, Inc. Albert accordance with ACCME Essentials.

Drs. Brumwell and Murphy report no conflict of interest. The authors report no discussion of off-label use. Dr. Fisher reports no conflict of interest.

Keratosis circumscripta, also known as been shown to improve, but not resolve, with kerat- circumscripta with palmoplantar keratosis, is a inolytic therapies. Some debate exists concern- rarely reported condition that manifests as well- ing the terminology used to identify this condition. circumscribed lesions consisting of grouped fol- Our report contributes to this ongoing dialogue liculocentric papules on the elbows, knees, neck, by presenting a case that supports recognizing sacrum, posterior axillary folds, and hips. This keratosis circumscripta as a unique clinical entity. condition typically begins in childhood and has We describe the diagnosis and treatment of a boy with keratosis circumscripta. We also present a review of the literature pertaining to this condition and an overview of the controversy surrounding Accepted for publication August 2, 2006. its terminology. Dr. Brumwell is a flight surgeon, Naval Test Wing Atlantic, Cutis. 2007;79:363-366. Naval Air Station, Patuxent River, Maryland. Dr. Murphy is a dermatologist, US Naval Hospital, Camp Lejeune, Jacksonville, Case Report North Carolina. Reprints: LCDR Eric P. Brumwell, MC, USN, Department of Military An 8-year-old African American boy presented in Medicine, Naval Health Clinic Patuxent River, 47149 Buse Rd, the summer of 2005 with a 5-year history of a rash Bldg 1370, Patuxent River, MD 20670 (e-mail: [email protected]). on his elbows, knees, and hips. The patient’s lesions

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papules. There was no change in color and the violaceous plaques still were sharply demarcated. Maintenance therapy with urea cream 40% provided sustained results with which the patient and his parents were extremely satisfied.

Comment Originally described by Shrank1 in 1966, keratosis circumscripta typically is associated with individuals of African descent, specifically descendents of the Yoruba tribe of Nigeria. Shrank1 identified lesions in 11 patients, all between the ages of 3 and 17 years and of the Yoruba tribe of Nigeria. The Keratosis circumscripta with symmetric areas of sharply demarcated follicular and scale in a lesions were described as “sharply defined areas of background of thickened violaceous plaques on the diffuse and follicular hyperkeratosis on the hands, extensor surfaces of the elbows and knees. feet, elbows, knees, and trunk.” The extensor surfaces of the elbows and knees always were affected, as was initially developed at 3 years of age and were described the trunk in the form of circular disks of follicular by his pediatrician as small 1- to 2-mm hyperkeratotic hyperkeratosis on each hip. The backs of the hands perifollicular papules on the elbows, knees, and hips and dorsa of the feet occasionally were affected, but that were hardly noticeable. From 3 to 6 years of age, the palms, soles, and nails rarely were affected. Biopsy the involved areas slowly developed into diffuse vio- results demonstrated follicular plugging and moderate laceous plaques that became thickened and markedly hyperkeratosis, with the lower layers of the epidermis more demarcated from the surrounding unaffected and dermis unaffected. The lesions developed in 2 to . For the 2 to 3 years prior to presentation to our 3 weeks between the ages of 3 and 5 years, and they clinic, the child’s lesions remained stable and did did not spread any further. Notably, Shrank1 reported not wax or wane independently. The patient never no adult cases. developed new lesions on other parts of his body. The Shrank1 initially thought that the disorder was lesions did not improve or resolve with sun exposure an acquired dermatosis. He specifically suspected and remained unresponsive to all therapies initiated hypervitaminosis A because the Yoruba tribe was by the child’s pediatrician, including various steroid known to cook much of their food in red palm oil, creams and emollients such as hydrocortisone 1%, a substance rich in vitamin A. He discounted this hydrocortisone 2.5%, triamcinolone acetonide 0.1%, diagnosis after determining that the patients’ serum Aquaphor®, Eucerin®, and Cetaphil®. levels of b-carotene and vitamin A were within ref- The boy was born in the United States and was the erence range. For the same reasons, he discounted third generation of an American family that emigrated a deficiency of vitamin B complex. The author also from Africa. The child’s parents denied knowing where suspected juvenile pityriasis rubra pilaris (PRP). in Africa their family had resided. The child had no Although he noted that the disorder shared some known relatives who were similarly affected. similarities with juvenile PRP, he reported that the Results of a physical examination revealed sym- children failed to improve with topical steroid and metric areas of sharply demarcated follicular hyper- oral vitamin A treatments. Also, his patients did not keratosis and scale in a background of thickened exhibit diffuse erythema or scaling of the scalp and violaceous plaques on the extensor surfaces of the face, findings that are associated with juvenile PRP. patient’s elbows and knees (Figure) as well as sym- Thus, Shrank1 concluded that sufficient differences metric lesions on each hip. The lesions were not existed between the conditions to merit recognizing erythematous, showed no scale between the follicles, the disorder as a separate entity. and were not micaceous in nature. The patient had Shrank1 then considered that the condition no skin thickening of the palms and soles or scaling could have represented a recessively inherited geno- of the scalp or face. The patient also did not have any dermatosis, noting that the children were all from lesions on his neck, buttocks, abdomen, shoulders, the same tribe and that their mothers and fathers popliteal fossae, or extensor surfaces of his arms. were not affected. However, he found no evidence of Four weeks after initiation of urea cream 40% any affected siblings, a strong argument against the applied twice daily to the affected areas, the patient’s disorder being an inherited condition. He also con- lesions were softer, smoother, and considerably less sidered 2 genodermatoses that closely resembled the hyperkeratotic, with resolution of the perifollicular clinical appearance of the cases that he followed.1

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These disorders were mal de Meleda and a hereditary that his patients’ lesions were stable over a period of condition described by Greither.2 Like the condition years and never resembled psoriasis. observed by Shrank,1 both of these genodermatoses A contemporary text describes keratosis circum- exhibit hyperkeratosis of the hands, feet, elbows, scripta as having folliculocentric papules grouped and knees; however, the trunk is never involved into well-circumscribed areas, predominately on as it is in keratosis circumscripta. Additionally, in the elbows, knees, neck, sacrum, posterior axillary mal de Meleda, the palms, soles, and nails always folds, and hips.6 Although similar to psoriasis, the are involved, and the disease progresses through histologic findings of keratosis circumscripta report- life, with eventual involvement of the elbows and edly do not show neutrophilic microabscesses, and knees.3 The described by Greither2 no evidence exists of patients with the disorder who was not consistent with what Shrank1 observed eventually developed psoriasis. The text notes that because it demonstrated an autosomal dominant lesions of keratosis circumscripta may improve with mode of inheritance. While maintaining that his exfoliant/emollient preparations such as topical cases could represent a genodermatosis inherited as urea cream 40%, cream 2% in urea an autosomal-recessive trait, Shrank1 concluded that cream 20%, or glycolic acid preparations. Salicylic the disorder he observed had sufficient differences acid peels and laser treatments also may prove to from these 2 genodermatoses for it to be regarded be therapeutic.6 as a separate entity, and he named the condition Kelly6 noted that keratosis circumscripta clini- keratosis circumscripta. cally overlaps with juvenile PRP and lichen spinu- In 1978, Soyinka and Laja4 published a report losus. Although all 3 conditions have well-defined that countered Shrank.1 Rather than keratosis plaques of hyperkeratoses on the elbows and knees, circumscripta, they proposed that Shrank’s1 patients the overall presentation and histology of keratosis suffered from an environmentally modified variant circumscripta are sufficiently different from juvenile of psoriasis. Upon investigating Shrank’s1 original PRP and lichen spinulosus, warranting its classifica- records, the authors reported that 4 of 11 biopsies tion as a separate clinical entity. The histologic find- were recorded as having had many characteristics ings in juvenile PRP are similar to those of keratosis that, in their opinion, reflected a variant of pso- circumscripta, with follicular plugging and mod- riasis. In particular, these characteristics included erate hyperkeratosis, and with the lower layers “destruction of basal layer with lymphocytic infil- of the epidermis and dermis unaffected. How- trations,” “elongation of the rete pegs,” “pointed ever, as observed in our patient, keratosis circum- rete ridges,” and “occasional intracellular oedema.”4 scripta typically does not have the thickening of Interestingly, Soyinka and Laja4 remarked that the skin of the palms and soles, which often is Shrank1 never referred to these characteristics found in juvenile PRP. Also, our patient’s lesions in his 1966 article and only described follicular did not demonstrate any erythema, and he did plugging, moderate hyperkeratosis, and occasional not have scaling of the face or scalp as can be parakeratosis. Based on their review of Shrank’s1 found in juvenile PRP. Additionally, juvenile PRP work, Soyinka and Laja4 proposed renaming this lacks the circular discs of follicular hyperkera- condition psoriasis circumscripta with palmoplantar tosis that were found on the hips of our patient, keratosis, a term that has since been used inter- which are consistent with a diagnosis of keratosis changeably with keratosis circumscripta despite the circumscripta.7 With respect to lichen spinulosus, lack of evidence definitively linking the 2 condi- our patient did not have plaques on the buttocks, tions to one another. abdomen, shoulders, popliteal fossae, or extensor In 1979, Verhagen5 continued the dialogue on surfaces of his arms as is usually seen with this this disorder, responding to Soyinka and Laja’s4 disorder. His lesions enlarged relatively slowly, conclusions and defending Shrank’s1 findings. Refer- rather than the rapid fashion reported in patients ring to his experiences in Kenya where he encoun- with lichen spinulosus. Furthermore, our patient tered about 10 cases similar to Shrank’s1 patients, demonstrated no erythema and his plaques were Verhagen5 reported that he found minimal similari- much more sharply demarcated than those found ties between keratosis circumscripta and psoriasis. in lichen spinulosus. His patients showed a type of hyperkeratosis “totally The controversy surrounding the naming of different” from that of psoriasis and exhibited “hardly keratosis circumscripta has resulted in the pseud- any dermal abnormalities, notably in the papilla, or onym psoriasis circumscripta with palmoplantar Munro’s abscesses.”5 Moreover, like those patients keratosis, which implies that the disorder is a variant described by Shrank,1 Verhagen’s5 patients did not of psoriasis. However, our case report and review of respond to corticosteroids. Also, Verhagen5 noted the literature suggest that keratosis circumscripta

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exhibits enough unique characteristics to war- Comment rant designating it as a separate clinical entity. Our clinical findings suggest that our patient had The name psoriasis circumscripta with palmoplantar keratosis circumscripta. This disorder has a distinc- keratosis would not fit our patient’s clinical presenta- tive symmetric, stable, nonprogressive, and sharply tion because he had no palmar or plantar lesions. demarcated clinical presentation. It demonstrates The patient’s well-circumscribed plaques had dis- resistance to treatments that would normally improve tinct follicular hyperkeratosis and scale, and the clinical entities such as psoriasiform lesions, juvenile lesions were in a background of thickened viola- PRP, and lichen spinulosus, all of which share some ceous plaques. However, there was no scale between characteristics associated with this disorder. Keratosis the follicles, which is inconsistent with psoriasis. circumscripta clinically exhibits folliculocentric pap- The patient’s scale was not micaceous and thick, ules grouped into well-circumscribed clusters on and there was a complete lack of erythema, both the elbows, knees, neck, sacrum, posterior axillary of which are common in psoriasis. The patient’s folds, and hips. Histologically, keratosis circumscripta lesions grew larger for approximately 3 years and shows follicular plugging and moderate hyperkerato- then remained stable, unlike lesions in psoriasis, sis, with the lower layers of the epidermis and dermis which often worsen throughout life. After 6 years of unaffected and showing no evidence of neutrophilic age, the patient’s lesions did not worsen with time; microabscesses. The condition appears to respond to they also did not lessen or resolve with sun exposure. keratinolytic therapies. Based on our clinical find- Additionally, the lesions did not respond to topical ings and review of the literature, we conclude that steroid treatments. All of these findings are atypical keratosis circumscripta is a unique clinical entity and for psoriasis, and the history, distribution, and char- that distinguishing it as such will facilitate our ability acteristics of this patient’s lesions resembled those to understand and appropriately treat this rare and originally described by Shrank.1 unique condition. The term keratosis circumscripta offers a diagnostic clarity that cannot be accurately achieved by using References the term interchangeably with psoriasis circumscripta 1. Shrank AB. Keratosis circumscripta. Arch Dermatol. with palmoplantar keratosis. In our patient, the term 1966;93:408-410. psoriasis circumscripta with palmoplantar keratosis is in 2. Greither A. Keratosis extremitatum hereditaria progredi- fact a misnomer because the patient did not have any ens with genetic dominant [in undetermined language]. palmoplantar lesions and his lesions did not resemble Hautarzt. 1952;3:198-203. psoriasis. Unlike psoriasis circumscripta with palmoplantar 3. Greither A. The Meleda disease (Mljet) [in German]. keratosis, the term keratosis circumscripta does not sug- Hautarzt. 1954;5:447-450. gest to a physician that corticosteroid therapy is an 4. Soyinka F, Laja AO. Keratosis circumscripta. a distinct der- appropriate treatment modality. Our patient did not matological entity or a variant of psoriasis? Dermatologica. respond to corticosteroid therapy, a course of interven- 1978;156:341-350. tion that would have likely improved his lesions had 5. Verhagen AR, Soyinka F, Laja AO. Keratosis circumscripta they been caused by a variant of psoriasis. Furthermore, [letters]. Dermatologica. 1979;159:182-183. keratosis circumscripta should be regarded as a distinct 6. Kelly P. Folliculitis and the follicular occlusion clinical entity because if the disorder is later deter- tetrad. In: Bolognia JL, Jorizzo JL, Rapini RP, eds. mined to be a genodermatosis, a possibility suggested by Dermatology. Vol 1. Philadelphia, Pa: Mosby; 2003: Shrank,1 its specific manifestations may facilitate our 553-566. understanding of the genetic mechanisms particular to 7. Jacyk WK. Pityriasis rubra pilaris in black South Africans. its expression. Clin Exp Dermatol. 1999;24:160-163.

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