Seven Cases of Senile Gluteal Dermatoses Developed with Ulcer.

Dear Editor:

Senile gluteal dermatoses (SGD) is the hyperkeratotic lichenified skin lesions around of the gluteal cleft which was first reported in Japan1. Distinctive skin lesions of SGD are brownish scaly plaques on the gluteal cleft and both sides of the buttocks assuming a pattern of “three corners of triangle” (Fig. 1). The prevalence is not known but it is thought to be common in Asia, relatively rare in the West countries2,3. The etiology is not known exactly, but old age, low body weight, prolonged sitting position, friction, and pressure are known to be related4. And the association between systemic diseases and SGD is thought to be not relevant yet.

Fig. 1

Senile gluteal dermatosis with ulcer (C: Patient no. 2, D: Patient no. 5). The predilection sites of ulcer with senile gluteal dermatoses (dark circles) and ‘three corners of triangle’ (triangle A: coccyx, B: ischial tuberosity).

We retrospectively collected the patients of SGD with ulcers (Table 1) from 2010 to 2014. The mean age of seven patients was 73.3 years (range, 67~87 years), and male/female ratio is 0.4 (2/5), and mean body mass index was 22.4. Duration of SGD was various from 2 weeks to 10 years. All ulcer lesions of SGD were negative for culture of bacteria and fungi. Skin biopsies were performed in three patients around the ulcer lesion and revealed epidermal hyperkeratosis, follicular plugging, and papillary dermal vascular dilatation. The treatments of these skin lesions were daily simple dressing with topical antibiotics. Duration of these treatments was various from 2 weeks to 6 weeks and the ulcers of all cases were recovered completely.

Table 1

Clinical manifestations in seven patients of SGD with ulcers

Patient no.	Age (yr)	Sex	Symptom	Underlying systemic disease	Duration		Biopsy	Duration of treatment (wk)
					SGD (yr)	Ulcer (wk)
1	0067	F	Tenderness	HTN, RA	10	4	O	3
2	0069	F	Pain	DM	Unknown	2	-	4
3	0069	M	Tenderness	HTN, DM, LC	2	3	-	4
4	0072	M	Pain	-	Unknown	2	-	3
5	0074	F	Itching	CVA, HTN, DM	Unknown	4	O	2
6	0087	F	Pain	CKD, CHF	Unknown	5	-	6
7	0075	F	Pain	HTN, DM	1	Unknown	O	3

SGD: senile gluteal dermatoses, M: male, F: female, HTN: hypertension, RA: rheumatoid arthritis, DM: diabetes mellitus, LC: liver cirrhosis, CVA: cerebrovascular accident, CKD: chronic kidney disease, CHF: congestive heart failure, -: none.

Ulcers in SGD on the cleft of the buttock should be differentiated form other several ulcer-developing dermatologic conditions as like herpes simplex, lichen simplex chronicus, pilonidal sinus etc. Among them, the differentiation with pressure ulcer is most important. Pressure ulcer has tendency to happen the skin area of bony prominence, especially in the status of prolonged immobilization. In buttock area, pressure ulcers are prone to occur in skin area on the sacrum, ischial tuberosity, and femoral trochanter5. But in SGD, ulcers are developed in lower position of gluteal cleft than pressure sore which happen due to force abrasively folded inward in both buttocks (Fig. 1). In the pressure ulcer, the most important etiologic factor is pressure. SGD patients developed with ulcer were all ambulatory unlike the pressure sore. And ulcers in SGD were observed in locations that force both gluteal regions to evert. Therefore, ulcers developed in SGD are more feasible to generate due to friction force chafed against both gluteal region and moisture covered up tightly.

In pressure ulcer, damage caused by pressure and shear force occurs in deeper tissue, in which the cutaneous injuries may be only the “tip of the iceberg” of the deeper lesion, more extensive damage. But, ulcers in SGD are thought to be affected by friction and produced by superficial injury. Duration of ulcer with SGD was relatively shorter than pressure ulcer and all ulcers with SGD patients were healed completely. As elderly people gradually increase worldwide, it is important that these ulcers should be recognized in SGD patients and distinguished from pressure ulcer.

In conclusion, the ulcers developed with SGD are thought to be produced by mainly friction more than pressure force in elderly peoples, and their locations different from that of pressure ulcers. And it is important to notice that these SGD ulcers have relatively shorter duration and better response of treatment than that of pressure ulcers, so it is necessary to avoid excessive treatment.