Dermatology Online Journal

Aplasia cutis congenita: A case report
Dr MR Vijayashankar
Dermatology Online Journal 11 (3): 28

Consultant Dermatologist, Gayathri Hospital, Vijayanagara POBangalore. metikurkeshankar@yahoo.com

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Abstract

Aplasia cutis congenita is a rare anomaly presenting with absence of skin. The most common site is the scalp. No definite etiology is available. Heredity is proposed with not much evidence. We present an instance with ACC occurring in both mother and son, suggesting a hereditary etiology.

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Introduction

Aplasia cutis congenita (ACC) is an uncommon anomaly of absence of skin. It may be localized or widespread. It most commonly presents as a solitary lesion of the scalp and may be as large as 70 percent of that site. Involved areas are well-circumscribed, not inflamed, and vary in size from 0.5 to 10 cm or larger. At birth lesions may appear as scars or ulcers [1]. On the scalp they may appear as parchment-like scars with alopecia.

Although usually benign, they may be associated with other physical abnormalities and syndromes. Frieden classified them into 9 groups based on the number and presence or absence of other anomalies [1]. Nearly 86 percent belong to the first group with a solitary lesion.

There is no racial or sexual predilection. It is present from birth.

The cause is not certain as it is the result of more than one disease process. Genetic factors, teratogens, compromised vasculature to the skin, and trauma are all implicated [1, 2].

Maximum tensile force during the development of scalp hair whorl is implicated for the scalp lesion. Early rupture of amniotic membrane forming amniotic bands may also be responsible [1].

In very few reports are histological details available; histological features vary depending on the depth of aplasia and duration. Ulcers are seen at birth. After healing, the epidermis appears flattened with proliferation of fibroblasts within a connective tissue stroma. Total absence of the epidermal appendages remains a characteristic feature [6].

If the defect is small it can be partially excised and then closed surgically.

Clinical synopsis

A 10-year-old boy of nonconsanguinous parents presented at Gayathri Hospital, Vijayanagara, Bangalore for a skin lesion that was present on the scalp since birth. The lesion was a circular patch of alopecia with thin skin.

Examination revealed a 2 cm semicircular atrophic parchment-like scar within which there was a total absence of hair (Fig. 1).

There were no other organ abnormalities on clinical examination. Radiological examination and ultrasonography of abdomen revealed no abnormalities. Routine investigations were with in normal limits. Later patient revealed that his mother also had a similar lesion. The clinical examination of the mother showed the presence of a similar patch at the same spot and the lesion was atrophic with parchment like scar and alopecia. She also had no other abnormalities clinically.

Figure 1	Figure 2
Figure 1. Skin lesion showing parchment like scar
Figure 2. After excision and suturing.

The lesion on the scalp of the boy was excised and the gap was sutured (Fig 2). Under histologic examination, the lesion showed moderate atrophy of the epidermis with absence of adnexal structures and an increase in collagen. No inflammatory cells were seen. (Fig. 3)

Figure 3
Figure. 3. Histopathologic examination (H&E) showing atrophy, fibroblasts, and collagen. No adnexal structures are evident.

Discussion

ACC is an uncommon disorder present at birth. The most common presentation is the solitary lesion on the scalp, as present in our patient. The peculiarity of this patient is that his mother had a similar lesion, possible evidence for a genetic influence. The presence of ACC in both mother and child is rare, but the condition has been noted in siblings [3, 4].

Congenital localized absence of skin is also seen in Bart syndrome [5], now considered to be a variant of epidermolysis bullosa [6].

There appears to be a clear genetic influence in many cases, but it is unlikely to be the same mechanism associated with each case. Friedan proposed a classification of ACC [6]. The clinical description of our patient points to type 1 of Frieden's classification.

The patient was treated with excision of the lesion, approximation of the wound, and suturing the ends (Fig. 3). The wound healed with no complication. Mother refused surgery.

Conclusion

ACC of the scalp in a mother and child presented for its rarity and as evidence of a genetic basis for this anomaly.

References

1. Mark. A Crowe, Aplasia Cutis Congenita. Section 2-9, e-medicine.com.inc. 2004.

2. Kruk Jeromin J, Jainik.J, Rykala T, Aplasia Cutis Congenita of the scalp, Report of 16 cases, Dermatolo.Surg, 1998 May, 24 (5).549-53.

3. Chitnis M.R, Carachi R, Galea.P. Familial Aplasia Cutis Congenita Eur.J.Pediatric Surg, 1996, Apr 6 (2) 100-1, PMID 8740132 [PubMed]

4. McMurray BR, Martin LW, St John Dignan P, Fogelsom MH. Hereditary Aplasia Cutis Congenita & associated defects. Three instances in one family & survey of a reported a case. Clin Pediatr (Phila) 1977 Jul 16(7) 610.4. PubMed [PubMed]

5. Ramón Ruiz Maldonado, personal communication.

6. Frieden IJ. Aplasia Cutis Congenita: a clinical review and proposal for classification cited in Rook / Ebling / Wilkinson, textbook of dermatology 6th edition. Ed: R. H. Champion et al 1998, Blackwell science Ltd.

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