Indian Journal of Paediatric Dermatology

: 2019  |  Volume : 20  |  Issue : 4  |  Page : 353--354

Asymptomatic freckle-like hyperpigmentation of the palms: A rare pigmentation caused by cydnidae (burrowing bug)

Rashmi Agarwal1, Sahana M Srinivas2, BS Chandrashekar1,  
1 Cutis Academy of Cutaneous Sciences, Affiliated to Rajiv Gandhi University of Health Sciences, Bengaluru, Karnataka, India
2 Department of Pediatric Dermatology, Indira Gandhi Institute of Child Health, Bengaluru, Karnataka, India

Correspondence Address:
Dr Rashmi Agarwal
Cutis Academy of Cutaneous Sciences, Bengaluru, Karnataka

How to cite this article:
Agarwal R, Srinivas SM, Chandrashekar B S. Asymptomatic freckle-like hyperpigmentation of the palms: A rare pigmentation caused by cydnidae (burrowing bug).Indian J Paediatr Dermatol 2019;20:353-354

How to cite this URL:
Agarwal R, Srinivas SM, Chandrashekar B S. Asymptomatic freckle-like hyperpigmentation of the palms: A rare pigmentation caused by cydnidae (burrowing bug). Indian J Paediatr Dermatol [serial online] 2019 [cited 2022 May 26 ];20:353-354
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Full Text


An 8-year-old girl presented to us with overnight onset of asymptomatic black-colored lesions on the left palm which she observed only in the morning. There was no history of fever, cough, or joint pain. There was no history of trauma before the onset of lesions. There was no history suggestive of contact with some chemicals in school or at home. On examination, she had multiple discrete brown to black pinpoint macules resembling lentigines of varying sizes over the medial aspect of the palm of the left hand with few lesions present on the central palm and fingers [Figure 1]. Few lesions had a streaky configuration. Few similar lesions were also present on the right hand. Depending on the nature of the pigmentation, a differential diagnosis of lentigines, pigmented contact dermatitis, purpura, and burrowing bug pigmentation were considered. She had attended a family function one day back along with her parents. She also gives a history of being involved in some outdoor activity at school the previous day. No other family members or friends at school were affected. The patches were nonblanchable and could not be wiped off with acetone. On dermoscopic examination, homogeneous black colored areas could be seen without any crusting or necrosis [Figure 2]. After 5 days, the dark patches disappeared on its own without any residual changes [Figure 3]. Based on the nature of the pigmentation and its property to heal spontaneously along with the history of being involved in outdoor activity, a diagnosis of burrowing bug pigmentation was made.{Figure 1}{Figure 2}{Figure 3}

Cydnidae bug, also called as burrowing or burrower bug, are arthropods of the order Hemiptera, distributed worldwide and includes more than 750 species in 93 genera, divided into six subfamilies. They have a dark ovoid body and measure about 2–20 mm globally. They are recognized by the morphological adaptations for digging, i.e., wide and flattened head, spiny legs, and modified tibia and tarsi. They burrow in the soil to feed on plants and are not routinely accessible. Adults usually live for 100 to 300 days. Burrower bugs have the capacity to fly in adult life during which they leave the ground to reach long distances and colonize new environment.[1] They release an odorous substance from special glands that serve as self-defense, can cause paralysis in prey and act as a danger signal. When it comes in contact with human skin, it can cause pigmented macules.[2] Here, we have described a child with sudden onset of asymptomatic pigmented macules over the palms which healed spontaneously without any residual changes due to burrowing bug. Certain other insects such as millipedes and blister beetles are also known to release chemicals that can cause erythema and hyperpigmentation after contact with fluids released by these insects.[3]

Malhotra et al. had reported similar pigmentary changes in three different cases, all occurring during the rainy season. They also collected similar insects from different places in these cases and experimentally reproduced the pigmentation by rubbing the insect firmly between the fingers and on the forearm. Unlike in our case, the pigmentation could be rubbed off using acetone, but the same could not be done using soap and water.[2] Similar cases with pigmentation were reported in two children during the rainy season, and as in the present case, the lesions could not be wiped off with either alcohol or soap and water.[4]

In our case, dermoscopy helped in ruling out other possibilities of acral melanocytic and lentiginous nevi, purpura, and pigmentation due to contact with chemicals. Dermoscopy of acral acquired melanocytic nevi shows one of three major patterns: the parallel furrow pattern, the lattice-like pattern, and the fibrillar pattern. Accidental staining with chemicals such as paraphenylenediamine or self-tanning products may show the parallel ridge pattern.[5] In our case, dermoscopy showed homogeneous brown-black pigmentation. Sudden onset of asymptomatic pigmented macules on exposed part with self-resolving nature and strong history of outdoor activity before the onset should raise the suspicion of Cydnidae (burrowing bug) pigmentation. Knowledge about this condition can prevent unnecessary interventions.

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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2Malhotra AK, Lis JA, Ramam M. Cydnidae (burrowing bug) pigmentation: A novel arthropod dermatosis. JAMA Dermatol 2015;151:232-3.
3Garg S, Bhalla M. Acral melanosis. Pigment Int 2018;5:14.
4Laad G, Shah S, Inamadar AC. Sudden-onset reddish-brown macules on the palms and soles of two children. Paediatr Dermatol 2017;34:605-6.
5Saida T. Dermoscopy of pigmented lesions of the palms and soles. In: Tsao H, Corona R, editors. UpToDate. Waltham, MA: UpToDate; 2018. [Last accessed on 2019 Jan 30].