Salt-and-pepper appearance: A cutaneous clue for the diagnosis of systemic sclerosis

Abstract

Sir, Systemic sclerosis is a multisystem disorder characterized by skin induration and thickening, fibrosis and chronic inflammatory infiltration of internal organs, microvascular damage and dysfunction, and immune dysfunction.[1] Systemic involvement may occur in the form of pulmonary vasculopathy, interstitial fibrosis, myocardiopathy, arrhythmia, conduction abnormality, acute renal crisis, lower esophageal incompetence, etc. [1] At times, the diagnosis of systemic sclerosis may be delayed, leading to increased morbidity and mortality. In these situations, a few clues may help in the early diagnosis of the disease. Systemic sclerosis is known to have cutaneous manifestations also; these include, especially, dyspigmentation in the form of a salt-and-pepper appearance; diffuse hyperpigmentation, with accentuation in sun-exposed areas (addisonian pigmentation); and hyper- and hypopigmentation in areas of sclerosis.[2] The salt-and-pepper appearance is characterized by the presence of vitiligo-like depigmentation with perifollicular pigmentary retention.[2] The rich capillary network surrounding the hair follicle preserves melanogenesis, and hence the retained perifollicular pigmentation in systemic sclerosis.[2] We have observed this salt-pepper appearance of the skin as one of the earliest features in systemic sclerosis in a few of our patients. With the aid of this finding early diagnosis was possible in these patients. Occasionally, this salt-and-pepper appearance may be the sole skin manifestation, i.e., without sclerosis of the skin (scleroderma sine scleroderma). In such situations an erroneous diagnosis of vitiligo may be made and the etiology of the underlying systemic problem, e.g., pulmonary fibrosis or hypertension, myocarditis or pericardial effusion, arthritis, etc., as the case may be, is missed. The patient may be dismissed with just symptomatic treatment. From June 2007 up to March 2011, we diagnosed systemic sclerosis in 16 patients. All patients fulfilled the American Rheumatism Association (ARA) diagnostic criteria for systemic sclerosis. Among the 16 patients, 15 had salt-and-pepper appearance of their skin and for 3 of these patients this was the presenting complaint. Commonly involved sites were the retroauricular area, scalp, forehead, neck, and the dorsa of the finger tips. In a study done in Nigeria among 14 patients, salt-and-pepper appearance of the skin emerged as the most common presentation.[3] In another study done at All India Institute of Medical Sciences, New Delhi, 51% of the patients had the salt-and-pepper appearance.[4] Not many studies are available on the prevalence of the salt-and-pepper appearance in patients with systemic sclerosis in Western countries. We feel that the light-colored skin in Caucasians may lead to poor contrast between depigmented and normal skin and poor appreciation of the salt-and-pepper sign in these regions, which is probably responsible for few cases being reported from the West. The salt-and-pepper appearance of the skin is presently considered as just one of many changes observed in the skin of patients with systemic sclerosis. However, we personally feel that the salt-and-pepper appearance of the skin, when seen along with sclerosis of the skin (one has to specifically look for the sclerosis), is a strong clue for the diagnosis of systemic sclerosis in people with types IV, V, and VI of skin (according to the Fitzpatrick classification scale). Recognition of this sign may help in the early diagnosis of systemic sclerosis.