Cutaneous Signs of Piety

Religious practices can lead to cutaneous changes, and awareness of these changes is of paramount importance in establishing the cause. We review the cutaneous changes related to religious practices, including the Semitic religions, Hinduism, and Sikhism (Table). The most widely followed Semitic religions are Christianity, Islam, and Judaism. Christianity and Islam collectively account for more than half of the world’s population.¹

Christianity
Christian individuals are prone to blisters that develop below the knees due to repeated kneeling in prayer.² A case of allergic contact dermatitis to a wooden cross made from Dalbergia nigra has been reported.³ Localized swelling with hypertrichosis due to muscular hypertrophy in the lower neck above the interscapular region has been described in well-built men who lift weights to bear pasos (floats with wooden sculptures) during Holy Week in Seville, Spain.⁴

Islam
Cutaneous signs of piety have been well documented in Muslim individuals. The most common presentation is hyperpigmentation of the forehead, usually noted as a secondary finding in patients seeking treatment of unrelated symptoms.⁵ Cutaneous changes in this region correspond with the area of the forehead that rests on the carpet during prayer. Macules typically present on the upper central aspect of the forehead close to the hairline and/or in pairs above the medial ends of the eyebrows; sometimes 3 or 4 lesions may be present in this area with involvement of the nasion (Figure 1).⁶

Figure 1. Three hyperpigmented macules from resting the forehead on a carpet during prayer.

In Saudi Arabia where Sunni Islam predominates, Muslim individuals observe prayer 5 times per day. Calluses have been observed in areas of the body that are frequently subject to friction during this practice.⁷ For instance, calluses are more prominent on the right knee (Figure 2) and the left ankle, which bear the individual’s weight during prayer, and typically become nodular over time (Figure 3). In Arabic, these calluses are referred to as zabiba.⁸

Figure 2. Keratotic plaques over the knees from prayer. Calluses are more prominent on the right knee.

A notable finding in followers of Shia Islam, which predominates in Iran, is the development of small nodules on the forehead, possibly caused by rubbing the forehead on a flat disclike prayer stone called a mohr during daily prayer,⁹ which is said to enhance public esteem.¹⁰ The nodules generally are asymptomatic, but some individuals experience minimal pain on pressure.⁸ Ulceration of the nodules has rarely been observed.⁷

Figure 3. Nodular callosity on the left ankle from prayer.

Limited access to thick and soft carpets and rarely bony exostoses or obesity are factors associated with prayer that can lead to skin changes (known as prayer signs), as they render the skin sensitive to pressure. Localized alopecia may occur on the forehead in individuals with low or pointed hairlines. An unexplained finding noted by one of the authors (K.A.) in some elderly Muslim individuals is that hair located on the forehead at the point of pressure during prayer remains pigmented, while the rest of the hair on the scalp turns white. Hyperpigmentation of the knuckles may be seen in individuals who use closed fists to rise from the ground following prayer. Except for mild hyperpigmentation of the knees,⁷ Muslim women rarely develop these changes, as they either do not pray,¹⁰ particularly during menstruation or puerperium, or they have more subcutaneous fat for protection.⁷ Some Muslim individuals who pray regularly at home may be conscious of these skin changes and therefore use a soft pillow to rest the forehead during prayer.

The histopathologic findings of prayer signs depend on the extent of lichenification and typically show compact hyperkeratosis or orthokeratosis, hypergranulosis, acanthosis, and mild dermal inflammation.⁸ Increased dermal vascularization and papillary fibrosis unlike that seen in lichen simplex chronicus have been described from skin changes in the lower limbs due to prayer practices.⁷ Additional findings in forehead biopsies include multiple comedones and epidermoid cysts in elderly patients showing a foreign body granulomatous reaction to hair fragments.¹⁰ Deposition of mucinous material in the dermal collagen in a prayer nodule on the forehead has been described in a Shiite individual, possibly due to repetitive microtrauma from the use of a prayer stone.⁹ Infections developed from sharing communal facilities or performing ritual sacrifices (eg, tinea,¹¹ orf¹²) are prevalent during the yearly Hajj pilgrimage at Makkah, Saudi Arabia, in addition to other infectious and noninfectious dermatoses.¹³ Muslim women wearing headscarves secured at the neck with a safety pin have developed vitiligo at that site due to friction.¹⁴ Occasionally, Muslim individuals may apply perfumes before prayers, which may cause allergic contact dermatitis.