dowling  degos disease ( ddd ) is a rare autosomal dominant condition characterized by multiple , small , round pigmented macules usually arranged in reticular pattern .
the lesions are chiefly distributed in axillae and groins , but other areas may be involved , including the intergluteal and inframammary folds , neck , scalp , trunk , and arms .
other features include scattered comedo - like lesions and pitted acneiform scars near the angles of the mouth .
dyschromatosis universalis hereditaria ( duh ) is an autosomal dominant condition characterized by hyperpigmented macules admixed with hypopigmented lesions involving the trunk , extremities , and the face .
herein we report three cases of ddd in a family with features overlapping with duh .
a 65-year - old male ( index case ) presented with lesions over his face , trunk , and axillae since the age of 25 years .
the lesions initially appeared over the face and later progressed to involve the axillae and trunk .
he was accompanied by his two sons , 40 years ( case 2 ) and 28 years ( case 3 ) of age , who had similar lesions since 23 years of age .
on examination , all the three cases had reticulate hyperpigmented macules over the neck , both axillae [ figure 1 ] and flexural aspect of both forearms . mottled hypopigmented macules were seen over the chest and abdomen [ figure 2 ] .
multiple pitted scars and open comedones with few cysts were present over the back [ figure 4 ] , chest and abdomen . hyperpigmented macules over the axilla in case 1 hypopigmented macules over the chest and abdomen in case 1 pitted scars over the perinasal and perioral area in case 1 comedones over the back in case 1 a skin biopsy performed from the index case showed elongated branched pigmented rete ridges [ figure 5 ] .
a diagnosis of ddd was arrived at based on the clinical and histopathologic findings , the atypical feature in these three cases being the presence of hypopigmented macules over the chest and abdomen .
histopathologic examination of the skin biopsy performed from the index case showing elongated branched pigmented rete ridges .
ddd is characterized by a triad of reticular pigmentation in the flexures , comedo - like lesions and pitted acneiform scars . the histology is diagnostic , with a distinct form of acanthosis , characterized by an irregular elongation of thin branching rete ridges , with concentration of melanin at the tips (  antler like appearance  ) .
follicular infundibulum may be involved and in some cases there is follicular plugging . in the present study ,
the association of ddd with reticulate acropigmentation of kitamura ( rapk ) has been earlier described in the literature .
vasudevan et al . reported a patient having overlapping features of ddd , rapk , and reticulate acropigmentation of dohi ( rapd ) .
there patient had acral pigmentation and palmar pits resembling rapk with flexural involvement resembling ddd .
they proposed that all these entities may be a part of the single pigmentary disorder . in the present study , all three cases had all features of ddd .
absence of palmar pits and acral pigmentation excluded coexistence of rapk ; however , the presence of hypopigmented macules admixed with hyperpigmented macules on the trunk suggested the coexistence of duh .
wu et al . described a family with autosomal dominant inheritance of a skin disorder with clinical features of both ddd and duh and they coined the term generalized ddd .
they believed that number of previously reported cases of ddd - rapk syndrome or ddd - duh overlap may be the cases of generalized ddd .
most patients in this group have the characteristic histologic findings of epidermal atropy , elongated rete ridges , horn cyst formation , and hyperpigmented tips .
the distribution may be reticulate in flexural areas ( classic ddd ) or generalized with hypopigmented papules ( generalized ddd ) .
histopathology of hypopigmented area shows elongation of rete ridges , basal hypopigmentation with pigment in the tip of rete ridges .
patients may or may not have atrophic brown macules on the back of hands and feet , palmar pits , and broken epidermal ridges , the entity known as rapk .
clinically , both have hyperpigmented and hypopigmented lesions ; and histopathology of hyperpigmented lesions shows basal hyperpigmentation and pigment incontinence , whereas hypopigmented lesions shows basal hypopigmentation .
although duh and dsh have similar histopathologic features , they differ from ddd group . in the present study ,
cases 1 , 2 , and 3 had lesions similar to the case described by wu et al .
galli galli disease ( ggd ) is the name given to a rare form of acantholytic ddd .
described a case of ggd in an indian family where 25 persons had ddd and they have been able to document a heterozygous nonsense mutation c.c10 t in exon 1 of the krt5 gene in four members of the family .
all the cases described by them showed a mottled pigmentation comprising hypo- and hyperpigmented asymptomatic macules similar to our case .
they pointed out that the hypopigmented lesions in the ddd spectrum has been underreported in india .
a similar mutation has been described in chinese family with ddd with hypopigmented macules adjacent to the classic lesions showing histologic features of ddd .
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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 can not be guaranteed .
 dowling  degos disease ( ddd ) is a rare autosomal dominant condition characterized by multiple , small , round pigmented macules usually arranged in reticular pattern , chiefly distributed in axillae and groins . 
 here we are reporting three atypical cases of ddd in a family . 
 they had hypopigmented macules with typical features of ddd indicating generalized ddd . 
 histopathology confirmed the diagnosis . 
 we present these three cases to stress the existence of generalized ddd phenotype in the indian population . 