|Year : 2020 | Volume
| Issue : 1 | Page : 36-41
A clinicoepidemiological study of eruptive hypomelanosis: A newly described entity
Savera Gupta, Manjaree Morgaonkar, Manoj Kumar Sharma, Suresh Kumar Jain, Anita Vijay
Department of Dermatology, Venereology and Leprology, Government Medical College, Kota, Rajasthan, India
|Date of Submission||29-Dec-2016|
|Date of Acceptance||12-Feb-2017|
|Date of Web Publication||24-Dec-2019|
Dr Suresh Kumar Jain
Department of Dermatology, Venereology and Leprology, Government Medical College, Kota - 324 005, Rajasthan
Source of Support: None, Conflict of Interest: None
Background: Eruptive hypomelanosis is a newly described entity from India characterized by sudden onset of symmetrical hypopigmented macules over the extremities. Only a few cases have been reported till date and the etiology is unknown. Aim: To study the epidemiological and clinical profile of eruptive hypomelanosis. Materials and Methods: A total of 19 cases were seen over a period of 5 months (March–July) and subjected to detailed history and clinical examination. Routine investigations including hemogram, liver and kidney function tests, urinalysis, erythrocyte sedimentation rate, C-reactive protein, HIV, hepatitis B surface antigen, anti-hepatitis C virus antibody, and potassium hydroxide (KOH) examination were carried out in all the cases. Skin biopsy was performed in three patients. Results: All patients were of pediatric age group ranging from 3 to 7 years (average 4.42 years) and had multiple discrete to confluent well-defined, hypopigmented nonscaly macules of size ranging from 2 to 20 mm, mainly distributed symmetrically over extensor aspect of extremities. Majority of the cases (12, 63%) presented in April. Six cases (37.5%) had prodrome symptoms 3 days to 2 weeks preceding the onset of lesions and four (25%) had positive family history. The routine investigations including KOH preparation and wood's lamp examination were normal in all cases. Histopathology of the skin was essentially normal. Lesions began to fade spontaneously after a period of 3–4 weeks resulting in complete/near-complete resolution, making total duration of the illness as 4–9 weeks. Conclusion: Considering the eruptive nature of lesions presenting in pediatric population, clustering of cases in a particular season, spontaneous resolution without active intervention, history of prodrome, and positive family history in some patients, eruptive hypomelanosis can be considered as a viral exanthem. As it can be easily confused with pityriasis versicolor, it is important for the clinicians to be aware of this entity so as to avoid unnecessary treatment.
Keywords: Eruptive hypomelanosis, exanthem, hypopigmented macules
|How to cite this article:|
Gupta S, Morgaonkar M, Sharma MK, Jain SK, Vijay A. A clinicoepidemiological study of eruptive hypomelanosis: A newly described entity. Indian J Paediatr Dermatol 2020;21:36-41
|How to cite this URL:|
Gupta S, Morgaonkar M, Sharma MK, Jain SK, Vijay A. A clinicoepidemiological study of eruptive hypomelanosis: A newly described entity. Indian J Paediatr Dermatol [serial online] 2020 [cited 2020 Jan 28];21:36-41. Available from: http://www.ijpd.in/text.asp?2020/21/1/36/273832
| Introduction|| |
Eruptive hypomelanosis is a newly described entity characterized by sudden appearance of asymptomatic, well-demarcated hypopigmented macules chiefly distributed over extremities in the pediatric age group. The etiology, pathogenesis, management, and prognosis of this entity are unknown, but based on history and clinical features, it is presently considered as a paraviral exanthem. Only a handful number of cases have been reported till date and all are from India.,, We encountered a few such cases and recorded their clinical and epidemiological profile.
| Materials and Methods|| |
It was a prospective study conducted in our department. Patients presenting with hypopigmented lesions were assessed and diagnosis of eruptive hypomelanosis was made on the basis of clinical presentation, i.e., sudden onset of asymptomatic hypopigmented macules and after ruling out other possible diagnosis such as pityriasis versicolor, pityriasis alba, progressive macular hypomelanosis (PMH), postinflammatory hypopigmentation on the basis of history, clinical examination, course of the disease, and relevant examination. A total of 19 cases were seen over a period of 5 months (March–July).
All cases were subjected to detailed history and examination. The history included age, sex, onset, duration and progression of lesions, associated symptoms, history of prodrome before onset of lesions, interval between prodrome and onset of lesions, similar case in a family member or neighborhood, course of the disease, history of drug intake or vaccination in the last 1 month, personal or family history of atopy. Thorough examination was carried out including wood's lamp examination. The following investigations were carried out in all patients - hemogram, liver and kidney function tests, urinalysis, erythrocyte sedimentation rate (ESR), C-reactive protein, antistreptolysin O titers, HIV, hepatitis B surface antigen, anti-hepatitis C virus antibody, and potassium hydroxide (KOH) preparation. Only three patients consented for skin biopsy.
| Results|| |
We encountered 19 cases of eruptive hypomelanosis over 5-month duration (March–July). The clinical and investigative profile of all cases is shown in [Table 1]. Majority of the cases (12, [63%]) presented in April. All were of pediatric age group (<18 years) ranging from 3 to 7 years, with mean age of 4.42 years. There were 13 (68%) males and 6 (32%) females, with male to female ratio being 2.1:1. All cases presented with a similar history of sudden appearance of hypopigmented lesions over extremities of duration ranging from 1 to 6 weeks. The morphology of the lesion was similar in all patients and can be described as multiple discrete to confluent, well-defined, hypopigmented nonscaly macules of size ranging from 2 to 20 mm. The macules were mainly distributed symmetrically over extensor aspect of extremities [Figure 1], [Figure 4] and [Figure 7]. Two cases (11%), however, showed flexural distribution of lesions [Figure 5] and [Figure 6]. One case (5%) showed distribution of lesions over face, extensor and flexor aspect of bilateral upper and lower limb, along with a few scattered lesions over trunk [Figure 2] and [Figure 3]. No abnormality was detected on nail and hair examination.
|Figure 1: Multiple discrete to confluent, hypopigmented macules over the extensor aspects of both thighs and knees with few lesions extending up to the legs (case 1)|
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|Figure 2: Multiple hypopigmented macules over (a) extensor and (b) flexor aspects of arms and forearms (case 2)|
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|Figure 3: Lesions present of face (a) nose (b) right temporal (c) left temporal with a few scattered lesions on trunk (case 2)|
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|Figure 4: Multiple discrete lesions over the extensor aspects of both thighs and knees, few lesions present over mons pubis (case 6)|
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|Figure 5: Involvement of buttocks, flexor aspect of thighs and legs (case 7)|
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|Figure 7: Lesions on extensor aspect of bilateral (a) upper and (b) lower limbs (case 17)|
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Most patients noticed progression of lesions for a few days after the onset. This was followed by a plateau phase, wherein the lesions ceased to progress and remained unchanged for a variable period ranging from 4 to 6 weeks. Subsequently, the lesions started to fade leading to complete or near-complete resolution and the total duration of the disease from onset to fading of lesions ranged from 4 to 8 weeks. Seven patients (37%) gave a history of prodrome symptoms such as fever, cough, coryza 3 days to 2 weeks preceding the onset of lesions. Other relevant examination findings such as erythema over palate and tonsillar area, cervical lymphadenopathy, inguinal lymphadenopathy, and fever were seen in 8 (42%) patients, of which six had prodrome symptoms. Lymph nodes were enlarged, discrete, slightly tender, and of size approximately 1–1.5 cm. Family history of similar clinical picture was positive in 4 (21%) cases, of which case number 9 and 10 were brothers. One patient (case number 8) gave history of similar self-limiting rash 1 year back, for which consultation was not sought. There was no history of drug intake and only one patient had received vaccination (Diphtheria, Pertussis and Tetanus) within 1 month before onset on rash. Personal or family history of atopy or any other skin disease was not obtained from any of the patients. A pediatric consultation was sought for each case and revealed no abnormality. All the cases were otherwise healthy, playful, feeding well, had uneventful perinatal history, and had appropriate physical, mental, and social development as per age, as assessed by attained milestones. Two patients were lost to follow-up.
Investigation profile of the cases was largely within normal limits. The minor abnormalities detected were ESR 29, hemoglobin 9, and total leukocyte count 2500 in cases number 3, 6, and 8, respectively. KOH preparation was negative in all the cases. Skin biopsy performed from the lesional skin revealed orthokeratosis, minimal focal epidermal spongiosis, and mild dermal perivascular lymphocytic infiltrate [Figure 8].
|Figure 8: Skin biopsy showing orthokeratosis and mild perivascular lymphocytic infiltrate (H and E, ×100)|
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| Discussion|| |
Eruptive hypomelanosis is a recently described entity from India by Zawar et al. As the name suggests, the disease manifests as sudden eruption of hypomelanotic macules in an otherwise healthy individual. The authors have described eleven such cases and considered it to be a paraviral exanthem as it is characterized by a prodrome of coryzal phase for 1–2 weeks preceding the onset of the eruption, eruptive nature of onset with successive crops of lesions, fairly uniform sizes of lesions, spontaneous resolution without active intervention, and relatively young age of children affected, thus indicating a primary infection rather than endogenous reactivation of a virus. They described the bilaterally symmetrical, hypopigmented macules over the extensor aspect of extremities and face in the pediatric population.
The cases presented here showed similar features. Clustering of cases was observed during a particular time of the year March–July in our region, with maximum number of cases seen in April. History of prodrome was present in almost half the cases. History of similar complaints in a sibling was significant in a few cases. Some cases showed erythema over palate and tonsillar area, cervical lymphadenopathy, and inguinal lymphadenopathy as the notable features on examination. These clinical and epidemiological features further favor the infectious etiology.
However, a few unreported findings were noted in our group of patients. In addition to cases with extensor distribution of lesions, we also encountered patients with flexural distribution, either alone or along with involvement of extensors. This was seen in three of our cases. Moreover, we noted a case with few scattered lesions over trunk.
Pityriasis versicolor was ruled out in each patient by KOH preparation of the scrapings from the lesions. The nonscaly lesions, sudden onset of the lesions, and site of involvement ruled out pityriasis alba. The absence of history of any inflammatory skin disease in the past makes postinflammatory hypopigmentation unlikely. PMH, also known as idiopathic multiple large macules or nummular and confluent hypomelanosis of the trunk, is a rare condition which is predominantly seen in young females and is characterized by symmetrically distributed ill-defined nummular, nonscaly, hypopigmented macules mainly on the trunk. This closely mimics eruptive hypomelanosis, but the lesions of PMH are comparatively larger in size, start to appear first on the trunk, tend to progressively increase in number, sometimes extending to the neck, face, buttocks and upper half of the extremities,, and persist indefinitely with little change. This is in contrast to the transient nature of lesions of eruptive hypomelanosis.
Lipsker and Saurat  have classified paraviral exanthems into three categories as follows - (i) clinically well-defined eruptions having many causes with at least one clearly primary infection or endogenous reactivation of viruses such as Gianotti–Crosti syndrome and papular-purpuric gloves and socks syndrome, (ii) typical and recognizable eruptions with viral infections or reactivations suspected as a triggering cause but which do not have a yet identified cause such as asymmetric periflexural exanthem and eruptive pseudoangiomatosis, and (iii) clinically very distinctive eruptions having long been classified as paraviral in dermatological nosology, but not due to solidly documented direct viral-related cytopathogenic effects such as pityriasis rosea. According to this classification, eruptive hypomelanosis may be placed in the second category as the causative organism is yet unknown.
Unfortunately, we could not perform further investigations due to resource constraints. For better understanding of etiology and disease pathogenesis, the following workup could be carried out - lesional and perilesional biopsy for histopathology, immunohistochemical staining, electron microscopy, DOPA oxidase reaction, staining for S-100, specimens from multiple body sites (lesion, throat, blood, bone marrow, lymph node) for polymerase chain reaction to detect DNA of various viruses, acute and convalescent sera for serological investigations to detect immunoglobulin M, immunoglobulin G against viruses, and their pattern of rise of titers. The results would help exploring this novel exanthem.
The temporary arrest of activity of melanosomes or destruction of epidermal melanin unit may be reason for hypopigmentation. The recent introduction of this entity in literature is not only interesting but also incites further research so as to learn the etiology, pathogenesis, prognosis, and management of the disease.
As mentioned earlier, only a few cases have been described till date. Since all the reports are from India, it is a subject to ponder over as to why there were no cases reported from other parts of the world. It could be possible that certain local environmental factors are responsible for disease confinement to a particular geographical region. Furthermore, hypopigmented macules may go unnoticed in those with fairer skin. Moreover, lack of symptoms and transient nature of rash may contribute to underreporting of cases. As children are predominantly affected and the lesions are self-resolving, the rash may be regarded as trivial by the parents. Even if consultation is sought, the pediatricians or physicians may not be aware of this presentation and may advice dermatology referral. The knowledge of this entity is essential so as to avoid misdiagnosis and unnecessary treatment. The condition may be easily confused with pityriasis versicolor, and hence, the possibility of eruptive hypomelanosis must definitely be kept in mind when a patient, especially a child, presents with sudden onset of hypopigmented nonscaly macules on extremities. Further reporting of cases, epidemiological and investigational studies are warranted to expand the knowledge and draw any definite conclusions about the etiopathogenesis of eruptive hypomelanosis.
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.
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Conflicts of interest
There are no conflicts of interest.
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