Tinea capitis - Irregular patch of alopecia with scaling and broken off stubs of hair within the patch. Multiple patches may develop. Occasionally the

involved (alopecia totalis). Hair loss may occur at other sites such as eyebrows, eye lashes, beard and body hair. Tr. - In majority, lesions regress spontaneously. Regrowth usually occurs within 3 months and only those patches that persist beyond this period require treatment. Topical corticosteroids may hasten recovery. Systemic corticosteroids (20-30 mg prednisolone) daily can produce regrowth of hair. 100 mg prednisolone once a week is equally effective. 2. Tinea capitis - Irregular patch of alopecia with scaling and broken off stubs of hair within the patch. Multiple patches may develop. Occasionally the patch may be inflamed (kerion). Tr. - Topical antifungal therapy is ineffective. Griseofulvin 10 mg/kg/day for 6 weeks or ketoconazole, itraconazole and terbinafine. 3. Lichen planopilaris - Lichen planus affecting hair follicles produces a patchy, scarring alopecia. Mimute, purple papules may be seen around hair follicles at the edges of the patches. Tr. - Clobetasol topically. If not controlled 20-30 mg prednisolone p. o. for 6-8 weeks. 4. Folliculitis Decalvans - rare cause with pustules around follicles which heal with scarring and destruction of hair follicles. T.r - Anti-staphylococcal antibiotics. 5. Skin diseases - that produce alopcia are discoid lupus erythematosus and morphoea. 6. Trichotillomania - produced by pt with psychiatric illness plucking her hair. 7. Traction alopecia - produced by tying a tight pony tail. This is most prominent along hair margins because distant hair is subject to most traction. Diffuse alopecia 1. Androgenetic alopecia - Loss of hair as result of androgenic hormones, hence the hair follicles that normally produce coarse terminal hair give rise instead, to vellus hair. The male type of alopecia has a typical pattern showing frontal recession of the hairline and thinning of the vertex. This may progress to involve the entire scalp except the occipto-temporal region. In women, the condition presents with diffuse alopecia with considerable thinning on the vertex. Tr. - Minoxidil lotion applied to scalp b. d. is of benefit in some who have thinning of the vertex, but require continued application. In women, anti-androgens can also be used and may be effective in some. 2. Telogen effluvium - Postpartum and postfebrile alopecia are not uncommon. There is diffuse loss of hair from entire scalp 2-3 months after pregnancy. This occurs because, following child birth, all the hair enter the resting phase (telogen) at the same time. All the hair are thus lost at the end of telogen which lasts 3 months. A similar mechanism underlies hair loss following fevers especially typhoid. Since there is no abnormality of the follicles, they begin to grow new hair immediately after the old hair are lost. 3. Drug-induced alopecia - Chemotherapeutic drugs exert a direct. inhibitory effect on the rapidly proliferating cells of the hair matrix and lead to hair loss. Recovery is usually complete after withdrawal of the drug. Other drugs include thiouracil, carbimazole, heparin, lithium, pyridostigmine and etretinate. 4. Alopecia of SLE - With subsidence of activity of the disease, hair regrow completely. 5. Alopecia of severe chronic illness - Diffuse hair loss may be a feature of a number of long-standing illnesses that cause constitu tional upset. 6. Idiopathic diffuse hair loss - mostly in women. Note: Surgery for alopecia is useful in diseases where there is a clear distinction between areas affected by disease and areas that are spared, e. g. androgenic alopecia, where the occipito-temporal fringe is never affected. Transplantation of hair from this area to bald areas is effective. G. URTICARIA Definition: Urticaria is a vascular reaction pattern characterized by transient, evanascent, pruritic wheals on the skin occurring on any site of the body. This, is a type I hypersensitivity reaction (IgE mediated immediate hypersensitivity) of the skin to a variety of exogenous and endogenous antigens. Vascular dilatation, the resultant dermal oedema and pruritus are caused by the release of histamine and other mediators from mast cells consequent upon binding of IgE antibodies to the antigen over cell surfaces. It is characterised by evanascent, pruritic wheals which last for 4-8 hours. When the subcutaneous tissue is involved it is termed angioedema. Provoking causes. A. Exogenous: 1. Ingestants: (a) Drugs e.g. penicillins, sulphonamides, aspirin, chloromphenicol, phenytoin. NSAIDs. (b) Foods e.g. seafoods, coloring agents (tartrazine), eggs, meat, spices, some vegetables, some dais, peas, etc. 2. Inhalants: pollens, plant, animal dander, dust, spores. 3 Injectants : Penicillins, insulin, antisera, vaccines. 4. Contactants : Bee stings, bug bites, animal dander, plants. B. Endogenous: 1. Infections: Chronic septic focus, UTI, virus infection (particularly hepatitis and respiratory tract infection), Candida infection. 2. Infestations: Helminths, amoebiasis, giardiasis. 3. Systemic diseases: SLE, lymphomas, malignant mastocytosis. 4. Psychogenic : Emotional stress. Types of Urticaria : 1. Ordinary urticaria - (a) Acute urticaria - lasts for a few hoursordays. It is characterized by the presence of small circumscribed areas of oedema, pink in colour, with central pallor. The number varies, and it occurs anywhere on the body asymmetrically. It is seen in patients with anaphylaxis, atopy, serum sickness or as a reaction to insect-bites, foods and drugs. (b) Chronic urticaria - Recurrent lesions for 3 months with or without arthralgias, adenopathy.