Phrynoderm E50.83

Nicholls L 1933

In Europe and the USA rare, chronic follicular keratinization disorder, observed mainly in Africa and Asia. In Europe after bypass surgery for obesity. Rarely during chronic dialysis for end-stage renal failure, Crohn's disease, or long-term inadequate vitamin A and B-deficient diets. Also in alcoholism (see also malassimilation syndrome).

However, a phrynoderm may also develop if a patient is on a calorie-restricted diet (< 700 kcal/d) and strictly avoids vegetables, fruits, and fats. The risk of malnutrition exists in patients who have been prescribed strict weight loss and those who may be in a malabsorptive state, such as patients who have undergone bariatric surgery. These patients should be recommended a balanced diet rich in vitamins A, B, C, and E, including foods such as yellow vegetables, green leafy vegetables, carrots, whole milk products, eggs, fish, and oils (e.g., fish liver oil, soybean oil, safflower oil, sunflower oil, corn oil, palm oil, cottonseed oil), as well as unprocessed cereal grains and nuts.

m:w=2:1

The lesions are typically dry, hard, pigmented papules with a 0.2-0.5 cm central intrafollicular keratotic plug protruding from the hair follicles in the form of horny spines resembling toad skin. However, the direct relationship between phrynoderma and vitamin A deficiency is controversial. Some reports suggest that this condition may occur secondary to general malnutrition or essential fatty acid deficiency. Night blindness associated with phrynoderma is rare but may occur associatively (see Case Report-Raveendra MS et al. 2010). An association with vitamin B complex deficiency is also possible. Of note is the occurrence of phrynoderma associated with chronic giardiasis (Girard C et al. (2006) Vitamin a deficiency phrynoderma associated with chronic giardiasis. Pediatr Dermatol 23:346-349).

First manifestation age in a larger study at 5-30 years, on average at 12-15 years.

Extensive sides of the extremities (picture of inflammatory keratosis pilaris) with knees and elbows, abdomen, back, buttocks. Face mostly free. Palms and soles always remain free (no follicles!).

Follicular, spinular or flat keratotic, skin-colored, pigmented or inflammatory papules, in vitamin A deficiency with dry, flabby, wrinkled and ashen skin. The follicular keratoses leave minute white scars (PIts) after healing.

See also avitaminosis, Bitot's spots, alcohol and skin lesions.

Raveendra MS et al (2010) reported on a three-year-old patient who presented with night blindness and was found to have skin lesions typical of phrynoderma. Both conditions resolved completely with vitamin A therapy, suggesting a causative role for vitamin A. The ocular manifestations of vitamin A deficiency are termed xerophthalmia, with the earliest manifestation being night blindness. Other manifestations include conjunctival xerosis, Bitot spots, corneal xerosis, keratomalacia, and corneal scarring.

Di Stefani A et al (2007) reported a 23-year-old man referred to our clinic with an 8-month history of severely pruritic lesions on the trunk and extensor sides of his extremities. Approximately 4 months before the onset of the lesions, the patient had begun a self-prescribed weight-loss diet that included avoiding green leafy vegetables, fresh fruits, oils, and eggs. In the year before presentation, his weight had decreased from 122 kg (body mass index 36.8 kg/m2) to 95 kg (body mass index 28.7 kg/m2). Clinical examination revealed multiple keratotic spiny papules and diffuse xerosis of the skin

Both patients were otherwise healthy, with no abnormalities of the mucous membranes, eyes, or body. The results of routine laboratory tests were all within the normal range; however, both men were deficient in several vitamins and minerals. The first patient's vitamin A level was 0.42 (normal 0.70-2.09) μmol/L, his vitamin E level was 10 (normal 12-42) μmol/L, and his zinc level was 8.4 (normal 12.2-24.5) μmol/L. The second patient also had low vitamin A (0.52 μmol/L) and vitamin E levels (9 μmol/L) and essential fatty acid deficiency (ratio of tri- to tetraenoic acid 0.5 /normal < 0.4). Histologic examination of skin biopsies from both patients revealed focal hyperparakeratosis, irregular acanthosis, and dilated hair follicles filled with keratin plugs .

Clinical differential diagnoses in both cases included phrynoderma, prurigo nodularis, follicular lichen planus, and Kyrle's disease. Both patients were diagnosed with phrynoderma due to faulty nutrition, and they received topical keratolytic ointments (urea 10-30%) and a balanced caloric intake (1500-2000 kcal/d) with nutritional supplements. These supplements included vitamin A (50 000 U/d for 1 month, then 5000 U/d for 2 months), vitamin E (alpha-tocopherol 300 mg/d), and vitamin B complex (thiamine 3 mg/d, nicotinamide 30 mg/d, riboflavin 1 mg/d, calcium pantothenate 1 mg/d, pyridoxine hydrochloride 0.5 mg/d, cyanocobalamin 5 mg/d), as well as vitamin C (500 mg/d) and essential fatty acids (safflower oil 5 ml/d). Both patients experienced complete regression of follicular papules within 3-6 months.

1. Abad L et al (2014) Phrynoderma After Biliopancreatic Diversion. Actas Dermosifiliogr doi:10.1016/j.ad.2014.08.009.
2. Bleasel NR et al (1999) Vitamin A deficiency phrynoderma: due to malabsorption and inadequate diet. J Am Acad Dermatol 41: 322-324.
3. Cobos G et al (2013) Phrynoderma in a patient with Crohn's disease. Pediatr Dermatol doi: 10.1111/pde.1226.
4. Di Stefani A et al (2007) Phrynoderma: a cutaneous sign of an inadequate diet. CMAJ 177:855-856
5. Girard C et al (2006) Vitamin a deficiency phrynoderma associated with chronic giardiasis. Pediatr Dermatol 23:346-349.
6. Maronn M et al (2005) Phrynoderma: a manifestation of vitamin A deficiency?... The rest of the story. Pediatr Dermatol 22:60-63.
7. Nakjang Y et al (1988) Phrynoderma: a review of 105 cases. J Dermatol 15: 531-534.
8. Nicholls L (1933) Phrynoderma: A condition due to vitamin deficiency Indian Med Gazette 68:681-687.
9. Raveendra MS et al (2010) Phrynoderma and night blindness. Indian Journal of Ophthalmology 58:175-176
10. Vogl A et al (2005) Skin and alcohol. J Dtsch Dermatol Ges 3: 788-790.
11. Sharma V et al (2011) Phrynoderma in a patient with megaloblastic anemia. Indian J Ophthalmol 59:72-73