Dermatology Online Journal

Multiple keratotic papules on palm
Piyush Kumar, Ashim Kumar Mondal, Kalyan Ghosh, Avijit Mondal, Ramesh Chandra Gharami, Satyendra Nath Chowdhury
Dermatology Online Journal 18 (1): 10

Medical College, Kolkata, India

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Abstract

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare nonhereditary malformation of the eccrine duct. A relationship with linear porokeratosis is not yet established; some consider it as a rare variant of porokeratosis involving the acrosyringium, whereas others consider it a separate entity based on distinctive clinical features and histologic accentuation within ostial structures. A 7-year-old girl presented with multiple asymptomatic keratotic papules over her right palm, present since the age of 6 months. These papules were arranged in a linear distribution over the palm and middle finger of the right hand. Most of the papules were discrete. However, lesions on the middle finger coalesced to form a plaque. Histology revealed a keratin filled deep invagination of the epidermis, notable for a column of parakeratosis (“cornoid lamella”). The dermis was notable for dilated eccrine ducts and absent inflammation. Considering the clinical and histological evidence, a diagnosis of PEODDN was made. Its clinical resemblance to linear lichen planus and linear porokeratosis is discussed. Also, we provide a brief review of this rare condition.

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Case report

Figure 1
Figure 1a. Multiple keratotic papules over the right palm in a linear distribution. Figure 1b. Close up of the lesions

A 7-year-old girl presented with multiple asymptomatic keratotic papules over her right palm since the age of 6 months (Figure 1). The lesion first appeared at the age of 6 months on the palmar surface of the middle finger of the right hand. Over time, new lesions kept appearing and involved the palm in a non-contiguous manner. The rest of the history was non-contributory.

On examination, multiple keratotic papules of similar size (2 mm to 3 mm) were found in a linear distribution over the palm and middle finger of the right hand. Most of the papules were discrete. However, lesions on the middle finger coalesced to form a plaque. Apart from these keratotic papules, a few pits were noted. The rest of the mucocutaneous and systemic examination did not reveal any abnormality. Linear porokeratosis, linear lichen planus, and PEODDN were considered in the differential diagnosis.

One of the papules was removed by punch biopsy and histologically examined. Histology revealed a keratin filled deep invagination of the epidermis. The invagination was notable for a column of parakeratosis (“cornoid lamella”). The dermis was notable for dilated eccrine ducts and an absence of inflammatory cells (Figures 2 and 3). The absence of a lichenoid infiltrate and basal layer vacuolar degeneration ruled out linear lichen planus. Porokeratosis rarely involves the acrosyrigium and exhibits perivascular infiltration containing chronic inflammatory cells [1]. The absence of such findings along with dilated eccrine ducts established the diagnosis of porokeratotic eccrine ostial and dermal duct nevus (PEODDN) in our patient.

Figure 2	Figure 3
Figure 2. H&E, x40 Figure 3. H&E, x400

Discussion

PEODDN is a rare nonhereditary malformation of eccrine ducts [2]. It was initially described by Marsden et al as comedo nevus of the palm [3]. However, it was Abell and Reed who coined the term in 1980 [3]. A relationship with linear porokeratosis has not been established. Some consider it as a rare variant of porokeratosis involving the acrosyringium [4]. Others consider it a separate entity based on the distinctive clinical features and the histologic accentuation within ostial structures [3].

It can present at birth or may have a late onset. However, a majority of cases present within the first few years of life. The lesions are mostly unilateral and are predominantly seen on acral parts, particularly over palms and soles [2, 3]. Lesions at sites other than the palm and sole, bilateral lesions, or extensive lesions following Blaschko lines have been reported [3]. On the palm and sole, it presents as multiple linear punctuate pits with comedo-like plugs and resembles nevus comedonicus [4]. Elsewhere, it presents as keratotic plaques and papules that resemble a linear verrucous epidermal nevus [3, 4]. Rarely, it may present as erosions in neonatal life and develop the classical appearance later on [3]. It is mostly asymptomatic but can be associated with pruritus, hyperhidrosis, or anhidrosis [4]. Various conditions have been reported in association with PEODDN. Some of these are palmoplantar keratoderma, psoriasis, anhidrosis, alopecia, nail dysplasia, Bowen disease, and squamous cell carcinoma [3, 4, 5]. Long-term follow up is recommended to identify and treat malignancy, although uncommon [3].

The common differential diagnoses of lesions on the palms and soles include nevus comedonicus, spiny keratoderma, or punctuate porokeratosis. Elsewhere, it should be differentiated from inflammatory linear verrucous epidermal nevus and linear porokeratosis [3, 4].

Histologically, PEODDN is characterized by a parakeratotic column (cornoid lamella) centered over a dilated acrosyringium. It shows a characteristic loss of the granular layer. Dilatation of eccrine ducts and sparse inflammatory cells in the dermis are noted. However, one case showed striking lichenoid infiltration and epidermal atrophy. Interestingly, this particular patient subsequently developed multiple in-situ and invasive squamous cell carcinomas in lesional skin [3]. At times, changes of PEODDN may involve the acrotrichium as well as acrosyringium. The condition is then known as Porokeratotic eccrine and hair follicle nevus (PEHFN) and is extremely rare [3].

The natural history is typically static and unremitting, but progressive extension of affected areas is known [4]. Treatment is not satisfactory. The ultrapulsed carbon dioxide laser has been used but requires multiple treatments and lesions may recur [3, 4]. Surgical excision may be considered for localized lesions [3]. Topical corticosteroid, calcipotriol, phototherapy, and cryotherapy have been largely unsuccessful. Topical retinoid, urea (10%), and short-contact dithranol may lead to some improvement [3, 4].

References

1. Johnson Jr. BL, Yan AC. Congenital diseases (Genodermatosis). In: Elder DE, Elenitsas R, Johnson BL, Murphy GF, Xu X (eds). Lever's histopathology of skin, 10th edition. Philadelphia, Lippincott Williams & Wilkins publishers, 2009;139-41.

2. Wang NS, Meola T, Orlow SJ. Porokeratotic Eccrine ostial and Dermal Duct Nevus: A report of 2 cases and review of literature. Am J Dermatopathol 2009;31:582-6 [PubMed]

3. Goddard DS, Rogers M, Frieden IJ, Krol AL, White CR, Jayaraman AG et al. Widespread porokeratotic adnexal ostial nevus: Clinical features and proposal of a new name unifying porokeratotic eccrine ostial and dermal duct nevus and porokeratotic eccrine and hair follicle nevus. J Am Acad Dermatol 2009; 61:1060.e1-14 [PubMed]

4. Pathak D, Kubba R, Kubba A. Porokeratotic eccrine ostial and dermal duct nevus. Indian J Dermatol Venereol Leprol 2011;77:174-6. [PubMed]

5. Sassannshausen J, Bogomilsky J, Chaffins M. Porokeratotic eccrine ostial and dermal duct nevus: A case report and review of literature. J Am Acad Dermatol 2000; 43:364-7. [PubMed]

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