Dermatology Online Journal

Lichen nitidus actinicus: A distinct facial presentation in 3 pre-pubertal African-American girls
Sapna Modi MD, Mandy Harting MD, Denise Metry MD
Dermatology Online Journal 14 (4): 10

Department of Dermatology, Baylor College of Medcine, Texas Children's Hospital, Houston, TX. msharting@sbcgloabl.net

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Abstract

Lichen nitidus is a relatively common inflammatory disorder of uncertain etiology seen primarily in the pediatric population. A rare variant may demonstrate a photodistribution of characteristic lesions. We describe 3 cases of lichen nitidus actinicus with prominent facial lesions.

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Introduction

Lichen nitidus (LN) is a benign, inflammatory skin disorder of unknown etiology most commonly occurring in children. This condition generally presents as clusters of small, pinpoint, round or polygonal-shaped, skin-colored papules with slightly raised, shiny surfaces. Occasionally, fine overlying scale or a hyperkeratotic plug may be seen. Lichen nitidus preferentially occurs on the abdomen, chest, genitalia, and upper extremities, and characteristically exhibits the Koebner phenomenon. Histopathology reveals a typical lichenoid tissue reaction, distinguished by the often-described image of a "claw clutching a ball." The ball represents a well-circumscribed area of lymphohistiocytic infiltrate near the epidermis, and the claw represents elongated rete ridges near the margins. Because LN tends to be asymptomatic and spontaneously regresses, treatment is unnecessary, though topical anti-inflammatories are often prescribed with variable success [1].

Lichen nitidus actinicus (LNa) is a rare variant of LN, which features lesions localized to sun-exposed areas of the body, typically the dorsal hands and the extensor forearms [1]. LNa has also been reported under the pseudonyms actinic lichen nitidus [2, 3] actinic lichenoid eruption, and summertime actinic lichenoid eruption (SALE) [4]. Herein, we describe 3 cases of LNa in prepubertal African-American girls, each of whom presented with an uncommon facial photodistribution.

Case Reports

Case 1

A 10-year-old African-American girl presented with an asymptomatic "rash" on her face for many months. On examination, she had numerous pinpoint, flesh-colored and hypopigmented papules on her central face, including both cheeks and dorsal nose. Her mother noted that the lesions seemed to worsen with sun-exposure. She had a similar eruption when she was 2 years-old, at which time the use of an unknown topical cream led to complete resolution. She had complete clearance with combination tretinoin 0.1 percent cream and pimecrolimus 1 percent cream (Table 1).

Case 2

A 6-year-old, African-American girl presented with an asymptomatic facial "rash" localized to her bilateral cheeks and nose. This first developed at age 3 years and was noted to worsen in the summertime with sun-exposure. On examination, she had many pinpoint, flesh-colored and hypopigmented papules on her bilateral cheeks and dorsal nose. (Fig. 1) She was treated with adapalene 0.1 percent gel and desonide 0.05 percent cream with no clinical response; however, her skin findings did partially improve over the following months (Table 1).

Figure 1	Figure 2

Case 3

A 6-year-old African-American girl presented with a 6-month history of asymptomatic bumps on her face, localized to her cheeks and nose. On examination, she had numerous pinpoint skin-colored papules on both medial cheeks and dorsal nose, and a few papules on her forehead. (Fig. 2) She was treated with topical pimecrolimus 1 percent cream and tretinoin 0.1 percent cream, with which she showed a partial response (Table 1).

Discussion

Lichen nitidus actinicus preferentially affects individuals of darker skin types (Fitzpatrick skin types IV and V) [3], having been described in persons of African, Middle Eastern, and Indian descent [1]. Lesions typically appear and/or are exacerbated during the summer months [2].

Lichen nitidus actinicus was first reported by Bedi in 1978 under the term summertime actinic lichenoid eruption (SALE) [4]. He described 25 Indian patients with discrete, pinpoint, flesh-colored papules on sun-exposed portions of the body, which appeared during the summer months and improved with sun protection. He recognized that the histopathology in these cases was distinct from that which had been previously described in lichen planus and lichen planus actinicus [4]. In 1981 Isaacson et al. described a similar case that was reported as actinic lichen planus. However, as the histopathology from several of these lesions was noted to be more consistent with LN than LP, the authors suggested that the term summertime actinic lichenoid eruption be used in favor of actinic lichen planus [5].

The term LNa was first proposed by Kanwar and Kaur in 1991 [6]. In 1998 Hussain supported this term over summertime actinic lichenoid eruption, in order to emphasize the parallelism between classic LN and classic lichen planus and between LNa and actinic lichen planus [3]. To our knowledge, only five cases of LNa have been described since 1998 [2, 7], with fewer than fifty total cases having been reported since Bedi's original description [1-6]. Only one of these cases described lesions occurring in a similar facial distribution as our patients [7].

In the cases described herein, all 3 patients presented with similar pinpoint, skin-colored and hypopigmented papules on the malar zone of the face, for which a clinical differential diagnosis included actinic folliculitis, follicular eczema, and Demodex folliculitis. Actinic folliculitis and follicular eczema may both be distinguished by their perifollicular nature and histological findings. Actinic folliculitis, a rare photodermatosis presenting 4-24 hours after sunlight exposure as a pustular eruption, histologically demonstrates inflammatory cells infiltrating the hair follicle [8]. Biopsy of follicular eczema reveals spongiosis with perifollicular parakeratosis [9]. Demodex folliculitis is very apparent by skin scraping or biopsy. While all of these conditions must be considered in the differential diagnosis, our cases are clinically most consistent with LNa. Although none of our families desired histopathologic confirmation, we believe that the lesion morphology, exacerbation and/or onset with sun exposure, and typical course support the diagnosis of LNa.

As most original cases were found in individuals of African, Middle Eastern, and Indian descent, LNa was initially thought to affect only persons living in subtropical areas. It is often excluded from dermatology texts [2]. More recently, however, LNa has been observed in the United States, first by Isaacson et al. in 1981 [5] and again by Glorioso et al. in 2006 [2]. We now describe 3 strikingly similar cases in pre-pubertal African-American girls. We hope this brief case series will call attention to a condition that may be overlooked and also to the rare facial photodistribution that has, to our knowledge, only been described once previously.

References

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2. Glorioso S, Jackson SC, Kopel AJ, et al. Actinic lichen nitidus in 3 African American patients. J Am Acad Dermatol 2006;54:S48-S9. [PubMed]

3. Hussain K. Summertime actinic lichenoid eruption, a distinct entity, should be termed actinic lichen nitidus. Arch Dermatol 1998;134:1302-3. [PubMed]

4. Bedi TR. Summertime actinic lichenoid eruption. Dermatologica 1978;157:115-25. [PubMed]

5. Isaacson D, Turner ML, Elgart ML. Summertime actinic lichenoid eruption (lichen planus actinicus). J Am Acad Dermatol 1981;4:404-11. [PubMed]

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7. Inamadar AC, Athanikar SB, Sampagavi W, et al. Actinic lichen nitidus. Indian J Dermatol Venereol Leprol 2001;67:209-10. [PubMed]

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