Indian Journal of Dermatology
: 2020  |  Volume : 65  |  Issue : 4  |  Page : 290--294

Dermoscopy of follicular dowling–degos disease

Garima Dabas1, Rahul Mahajan1, TP Afra1, Dipankar De1, Sanjeev Handa1, Divya Aggarwal2, Bishan Das Radotra2,  
1 Department of Dermatology, Venereology and Leprology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
2 Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Correspondence Address:
Rahul Mahajan
Department of Dermatology, Venereology and Leprology, Postgraduate Institute of Medical Education and Research, Sector 12, Chandigarh - 160 012


Dowling–Degos disease (DDD) is a late-onset genodermatosis characterized by hyperpigmented macules on the flexures along with scattered comedo-like lesions and pitted acneiform scars. Follicular Dowling–Degos is a rare type of DDD, with only two reports so far. It presents with follicular papules and comedo-like lesions predominantly on the face and trunk. Dermoscopy of follicular DDD shows irregular star-shaped/Chinese letter pattern pigmentation along with comedo-like lesions. Herein, we describe diagnostic clues including dermoscopy in three patients of follicular DDD which can help in differentiating it from other disorders presenting with comedo-like lesions .

How to cite this article:
Dabas G, Mahajan R, Afra T P, De D, Handa S, Aggarwal D, Radotra BD. Dermoscopy of follicular dowling–degos disease.Indian J Dermatol 2020;65:290-294

How to cite this URL:
Dabas G, Mahajan R, Afra T P, De D, Handa S, Aggarwal D, Radotra BD. Dermoscopy of follicular dowling–degos disease. Indian J Dermatol [serial online] 2020 [cited 2023 Jun 7 ];65:290-294
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Full Text


Dowling–Degos disease (DDD; MIM 179850) is a late-onset genodermatosis characterized by numerous, symmetrical, hyperpigmented macules over the axillae, groins, face, neck, arms, and trunk along with scattered comedo-like lesions (dark-dot follicles) and pitted acneiform scars.[1] It occurs due to a dysfunctional mutation in the keratin-5 gene on chromosome 12q, leading to abnormal pilosebaceous epithelial proliferation.[1] Other reported mutations include POFUT1 (encoding protein O-fucosyltransferase 1) and POGLUT1 (encoding protein O-glucosyltransferase 1).[2] Several atypical presentations of DDD have been reported in literature, such as those in association with other dyschromatoses, mimicking chloracne,[3] acantholytic variant, or Galli–Galli disease. Herein, we report three cases of the follicular variant of DDD. There have been only two previous reports of follicular DDD,[4],[5] and dermoscopy of this variant has not been described previously. We seek to highlight this rare variant with the help of dermoscopy and differentiate it from other conditions that manifest with follicular keratotic macules, papules, and pitted scars.

 Case Report

A 35-year-old female presented with asymptomatic, hyperpigmented lesions on the face, upper trunk, and flexures for 12 years. Her mother, younger sister, and elder brother had similar lesions. On examination, multiple hyperpigmented macules, 1–3 mm keratotic follicular papules, open comedones, and pitted scars were present on her face, neck, chest, back, and abdomen [Figure 1]a, [Figure 1]b, [Figure 1]c. Dermoscopy in polarized mode using ×10 magnification revealed a brown pigmentation in Chinese letter pattern/irregular star shape, central brown follicular plugs, and comedones [Figure 1]d and [Figure 1]e. Histopathology of skin biopsy showed follicular plugging with elongated, branching epithelia and the downward proliferation of infundibular wall with increased melanization at their tips and sides. The interfollicular epithelium was not involved, suggestive of follicular DDD [Figure 1]f. She was prescribed oral isotretinoin, which led to reduction in the follicular lesions and comedones. However, the improvement was partial and reversible on treatment interruption.{Figure 1}

Patient 2 was a 43-year-old female who presented with hyperpigmented lesions over her face, neck, upper chest, and flexures for the past 16 years. A history of similar lesions was present in her grandfather, father, three daughters, and a son. On examination, she had multiple scattered comedo-like lesions over the face, chest, and upper back and pitted perioral scars. Axilla and groin were not involved [Figure 2]a, [Figure 2]b, [Figure 2]c. On dermoscopy, brown pigmentation in Chinese letter pattern/irregular star shape surrounding the follicular plugs and comedones was observed [Figure 2]d and e]. Histopathology showed similar appearance as in the patient 1 [Figure 2]f. She was also prescribed oral isotretinoin 30 mg/day, which led to mild improvement. However, isotretinoin had to be discontinued because of transaminitis.{Figure 2}

Our third patient was a 54-year-old male who presented with an 18-year history of multiple comedones and pitted scars over his face, upper chest, and back. His father, brother, and daughter had a similar illness. On examination, multiple comedones and pitted scars were seen over the face, neck, axilla, upper chest and back. He also had associated acne, unlike other two patients [Figure 3]a, [Figure 3]b, [Figure 3]c. Dermoscopy and histopathological findings were similar to that of patient 2 [Figure 3]d, [Figure 3]e. The patient refused treatment with retinoids and was lost to follow-up.{Figure 3}


DDD is an autosomal dominant genodermatosis with variable penetrance, as seen in our series where many members of each family were affected. It presents as an acquired hyperpigmentation of the flexures, beginning in adult life. Most of the patients in our series also had onset in the second decade with a female predominance. Genodermatosis can present with a myriad of clinical presentation owing to different genetic defects and variable penetrance. A few reports including the present case series have highlighted the possible role of follicular pathology in the genesis of DDD, and the indicators include multiple comedo-like lesions, predominantly follicular hyperkeratotic papules, association with acne, hidradenitis suppurativa, and prominent infundibular changes on histology.[6] Recently, Zhou C et al. identified mutation in γ-secretase subunit of PSENEN encoding presenilin enhancer protein in DDD patients and reported that this subset of patients had an increased susceptibility to acne inversa.[7]

The unique features in our series are (1) early onset of disseminated comedones in adolescence in all three families; (2) the presence of very few hyperkeratotic follicular papules which became more apparent with dermoscopy and predominantly comedonal lesions; (3) a predilection for the face, neck, and upper trunk, rather than the extremities; (4) relative sparing of axilla and groin with only few scattered comedones over these sites; (5) the absence of classical reticulate pigmentation; and (6) classical histopathological changes confined to follicular infundibulum. The atypical presentation in our series led us to consider a number of other differentials listed in [Table 1]. Kershenovich et al. reported a case of DDD mimicking chloracne.[3] Diffuse familial comedones, familial comedones, idiopathic disseminated comedones, and familial disseminated comedones without dyskeratosis all belong to the same spectrum of disease with similar clinical manifestations. Our series highlights the heterogeneity of the disease and need for genetic studies to find out more about this association.{Table 1}

Dermoscopy in these patients helped in differentiating it from other diseases presenting with only comedones such as familial dyskeratotic comedones and chloracne. Classical histopathology helped in clinching the diagnosis of follicular DDD as the branching, elongated, hyperpigmented rete ridges were restricted to the follicular epidermis. Dermoscopy of the DDD has been described only once previously and it shows an irregular star-shaped brown outline on a red–brown background along with follicular plugging and inclusion cysts.[11] In our series, this irregular star-shaped or linear thready pigmentation in Chinese letter pattern was seen on normal skin as well as hyperpigmented background. In patient 3, these irregular star-shaped structures were present over follicular papules, suggestive of follicular DDD. Thus, dermoscopy can be used as a tool to diagnose follicular DDD.

The management of DDD is difficult. Although the lesions in DDD are asymptomatic, involvement of face is very distressing, increasing the psychological disability of the patients. Retinoids have proved ineffective in DDD, and Er:YAG and fractional CO2 are being considered to decrease pigmentation in DDD.[12] Our patients presented with predominantly comedones; therefore, oral isotretinoin was initiated, and the patients are being followed up to assess long-term safety. To conclude, presence of follicular papules, comedones, and pitted scars along with classical irregular star-shaped/Chinese letter pattern on dermoscopy are diagnostic clues for follicular DDD.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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