2.2. COMPOSICIÓN DE LA SALA DE ALCALDES
2.2.5. EL ALCALDE DE OBRAS Y BOSQUES
sign of pha langeal follicular hyperkeratosis is considered pathognomonic of PRP (Fig. 31.1).
The interfolli cular skin, initially normal, tends to become erythematous and scaly and papules appear to coalesce. The acuminate, follicular papules are lost at this stage except over the dorsa of the phalanges. Erythema and scaling extends to form large, welldemarcated plaques and may involve whole of the skin surface, simu lating erythro derma. However, these plaques contain small islands of apparently normal skin, a hallmark of PRP. The scaling is fine and powdery and is likened to the bran of the wheat. It is termed pityriasiform or fur
furaceous. Scaling is most marked on the face.
Figure 31.1: Pityriasis rubra pilaris. Small yellow pink acuminate papules over dorsum of the hand (Sehgal VN et al: Pityriasis rubra pilaris in Indians. Br J Dermatol 121: 821-22, 1989)
150
Textbook of Clinical Dermatology Palmoplantar hyperkeratosis develops earlyin the disease. It is yelloworange, thick with painful fissure and may extend to the sides of the feet, producing a ‘keratodermic sandal’.
Scalp shows fine and powdery scaling.
However, hair loss is uncommon.
Nails may develop longitudinal ridg
ing, sub ungual hyperkeratoses, and splinter hemo r rhages.
Oral lesions may be present, consisting of dif fuse, whitish, ground glass appearance, lacy white plaques, white spots and lines, and erosions.
Type II: It is characterized by ichthyosiform scaling. Eczematous change may develop over it. The scalp hair is often sparse. Keratoderma is coarse and lamellated.
Type III: It resembles classical adult PRP except that its onset is during the first two years.
Type IV: It affects prepubertal children and is characterized by erythematous follicular hyper
keratosis localized to the elbows and the knees.
It has no tendency to progress to classical PRP.
Type V: It begins during the first few years of life and is characterized by erythematous folli cular hyperkeratosis and sclerodermalike change in the hands and feet. Most familial cases belong to this group and it tends to run a chronic course.
About 50 percent of the patients remit within 3 years. Prognosis is excellent in classical adult onset (Type I), moderate in circumscribed juve nile (Type IV). Atypical juvenile (Type V) shows no tendency to remit.
Diagnosis
The diagnosis of PRP is clinical. The histolog
ic changes of PRP, though distinctive, are not diag nostic and only supplement the clinical diag nosis. The histologic features are: (i) follic
ular keratin plug surrounded by perifollicular
para keratosis, (ii) diffuse hyperkeratosis, (iii) mild irregular acanthosis, (iv) A mild, chronic, perivas cular infiltrate in the superfi
cial dermis, (v) liquefaction degeneration of the basal layer (Fig. 31.2).
The lesions of PRP though characteristic, have to be differentiated from the following: (i) sebor
rheic dermatitis, (ii) psoriasis, (iii) phry noderma, (iv) follicular eczema, (v) keratosis pilaris, (vi) Darier’s disease, (vii) lichen spinosum.
treatment
Although many agents have been used in the treatment of PRP (Table 31.1), the results have not been consistent. However, oral vitamin A forms the mainstay of treatment. It is given in a high dose of 150,000 to 500,000 IU daily.
Vitamin E, having an apparent synergistic affect,
Figure 31.2: Pityriasis rubra pilaris(H and E × 50)
151
Pityriasis Rubra Pilaris
table 31.1: treatment of PrP
Treatments Status
1. 50,000 to 300,000 units of vitamin A every day for It may be combined with 1600 IU of vitamin E to reduce
a prolonged period the dose and toxicity of vitamin A
2. 1 million units of vitamin A every day for 5 to 14 It is a toxic dose and predisposes to liver toxicity,
days hypertriglyceridemia, neurologic abnormalities,
increases the clotting time, alopecia, arthralgia, bone pain and teratogenecity
3. 0.75 mg/kg of etretinate every day It useful in erythroderma secondary to PRP 4. 2.5 mg of methotrexate once a day
-do-5. 1 mg/kg of prednisolone administered in 2 equally -do-divided doses at 9 a.m. and 6 p.m
6. Topical application of retinoic acid and other keratolytic agents
may be combined as an adjuvant to vitamin A.
This helps reduce the dose of vitamin A and its potential toxic effect. This may be combined with bland emolients and keratolytic agents. Other agents in vogue for treatment of PRP are: (i) 13cisretinoic acid (isotretinoin), (ii) etretinate, (iii) methotrexate, which unlike psoriasis, has to be administered in the daily dosage of 2.5 or 5 mg (iv) aromatic derivatives of retinoic acid such as Ro109459, (v) systemic steroids, (vi) stano zolol, which elevates the reduced levels of retinol binding protein, considered as basic anomaly in PRP.
reCommenDeD reaDing
1. Cohen PR, Prystowsky JH. Pityriasis rubra pilaris:
A review of diagnosis and treatment. J Am Acad Dermatol 1989;20:801807.
2. Fox J, Odom RB. Papulosquamous diseases: A review. J Am Acad Dermatol 1985;12:597624.
3. Griffiths WA. Pityriasis rubra pilaris. An histori
cal approach 2. Clinical features. Clin Exp Dermatol 1976;1:3750.
4. Griffiths WA. Pityriasis rubra pilaris: Review. Clin Exp Dermatol 1980;5:105112.
5. Sehgal VN, Bajaj P, Jain S. Pityriasis rubra pilaris (PRP): Report of four cases. J Dermatol (Tokyo) 2000;27:174177.
Lupus erythematosus is a chronic inflamma
tory, immune mediated collagen vascular dis
order with multisystem involvement. Genetic predis po si tion, environment, drugs, and immune system interact in the pathogenesis of this multi factorial disorder. The cutaneous presentation in lupus erythematosus may be the primary expres sion, or part of this multisys
temic disease. The skin lesions can be acute, subacute, or chronic. In fact, lupus erythemato
sus is perceived to form a spectrum with discoid lupus erythematosus and systemic lupus erythematosus as its polar expressions. Discoid lupus erythematosus (DLE) is characterized by the disease activity limited to the skin with minimal or absent systemic/serologic abnorma
li ties. Systemic lupus erythe ma to sus (SLE) is a multisystem disorder, and signs and symp
toms of systemic involvement may overshadow the often subtle form of skin changes. The two polar forms are bridged by sub acute cutaneous lupus erythematosus (SCLE). It is intermediate in severity between discoid LE and systemic LE. The systemic involvement is usually mild, affecting the musculoskeletal system. Central nervous system and renal system may be mildly affected or spared. Classification of lupus erythe matosus and its subsets is outlined in Table 32.1.